ON ARMY COMPOSITION AND UNIT SIZE

[Viking1978]

Intro
Like some of you I have studied the composition of the different kinds of legions with the intention to find an appropriate unit size, while staying as close as possible to history. There are only a few sources who relate the exact amount of soldiers in a legion and some are even contradictive, but of course, we have an idea and that's what the following short analysis is based on.

Firstly, to add the officers and other extra personnel would also give an entire different amount and while we have an idea about the Roman armies, we hardly have any idea of how it was in all the other cultures. So, for simplicity's sake it is better to keep the main troop sizes without these extras, the same way they do it in the vanilla game (e.g. 480 rather than 510 men per cohort and 800 rather than 825 men per first cohort), although it should be kept in mind that officers etc. really made a difference. In a way you leave out the most elitary soldiers as a centurion, for instance, was the one who first got in and last came out of a fight when his century was in melee. As to the amount of these extras, there were at least 305 extra personnel in a reformed army, not talking about the “camp followers”, but only including 1 legatus legionis, 1 tribunus mil lat., 1 praefectus castrorum, 1 aquilifer, 1 imaginifer, 5 tribunus mil ang, 59 centurios, 59 optios, 59 signifers, 59 tessarii, and 59 cornicens.
Concerning Roman cavalry, the original amount of 300 legionary cavalry from the republican regular legions gradually decreased towards the 120 equites legionis of an imperial army. Another source speaks of 180 equites legionis and 120 equites singulares legati, but it is not clear there if he speaks of one or two legions. But the number probably decreased, mainly because they were reserved for nobility (which was expensive) and replaced by cheaper auxiliaries. Cavalry consisted of an amount of turmae, groups of 30, 32, or 33 mounted soldiers (depending on the source). In republican armies the wings were usually formed by additional allied forces, both infantry and flanking cavalry, the so-called ala dextra (right wing) & ala sinistra (left wing), whereas the regular legion usually was positioned in the centre. In reformed armies, auxiliary cohorts were used for this. They were all independent, equal cohorts, and apart from extra infantry, auxiliaries were mostly the "specialised" forces (e.g. cavalry, missile cohorts, etc.). I speak of independent in the sense that there was no hierarchy like in the regular cohorts where e.g. cohorts I and X were for veterans, whereas cohort II for new legionaires. They were not grouped in or belonged to a legion, but were exchanged between legions where appropriate.
Artillery, when it started being used and transported, was divided among the cohorts themselves, 1 artillery piece per cohort and 10 soldiers taking care of it during battle.
Reformed legions should have slightly bigger unit sizes than republican. Marius organised them into cohorts which brought about a change from 420 to 480 soldiers per unit + a bigger first cohort.
As to bodyguards, they were privately hired in those days and varied. In addition, it was probably not only a general who had them, but also his high-ranking officers. It is known that Caesar at some point had at least a bodyguard of 300 Germanic warriors and this was probably no exception. Centuries later, there were the bucellarii of which Belisarius had up to 7000 at some point.

Anyway, bearing all this in mind, I came to the following conclusions:

Key features
- have cav and missile units with the same unit size as infantry units, but in most cases, less units per stack for auto-generation.
- have general bodyguards include regular legionary cavalry: respectively (minimum 300 cav + 100 bodyguards) and (minimum 120 cav + 360 bodyguards), rendering a normal legionary unit.
- a regular Roman legion consists of 11 units: 1 general, 9 regular troops, 1 larger troop, a general army (non-Latin) equivalent: 1 general, 10 larger troops
- a unit size ¼ of reality is most suitable to represent the different kinds of legions; ½ would be possible if we would not have the pathfinding trouble in the game. In the case of ¼ the maximum unit size is 150, with the exception of the first cohort (and perhaps a Praetorian guard) which counts 200, but which is capped at 1 per army.
- +50% larger armies for other cultures than republican regular legion, +25% larger than reformed legion.
- very cheap Roman republican legionaires (who have 2/3 amount of troops of other factions), as they were also supposed to provide their own equipment) compared to the reformed “cohort” legionaires (who have 4/5 amount of troops of other factions), but capped per army according to a legion: 3 velites, 3 hastati, 3 principes, 1 triarii. Other caps include 9 cohorts, 1 first cohort, and I would suggest 1 praetorian guard (even in a whole campaign, I think that is still possible with the "campaign_total_cap"? I would mainly suggest the use of praetorian guards as garrison units of big cities).
- for artillery a cap of 2 per kind, but have units with 5 artillery pieces and 25 men... auto-generation set to a max of 4 artillery units per stack.
- the same size for all auxiliary units as regular troops, which means 100 for republican & 120 for reformed auxiliaries.
- MERC and AOR unit size like non-Latin factions: 150 per unit (but there should not be any Latin ones).

* I speak of non-Latin rather than non-Roman to include other Latin factions

Army composition (main troops)
As mentioned before, unit sizes are based on the regular main troops only, not the extras (officers etc.) which e.g. for a reformed army would be 305, rendering a total of 5545 troops (without bodyguards). The smaller cavalry units are joined with mounted bodyguard to form a complete general's unit.

Republican Regular Legion
A normal republican legion:
1200 velites, 1200 hastati, 1200 principes, 600 triarii, 300 equites > 4500

Legion in game: 300 (3x100), 600 (3x100), 900 (3x100), 1050 (1x150), 1150 (1x100: general, equites, & bodyguard)
Legion in real: 1150x4 > 4600
Full stack in game: between 2050 (+9x100) and 2500 (9x150)
Full stack in real: between 8200 and 10000
Full stack with max artillery in game: between 1750 (+5x100, +4x25) and 2000 (+5x150, +4x25)
Full stack with max artillery in real: between 7000 and 8000

Reformed Regular Legion
A normal reformed legion:
4320 (9 normal cohorts of 480), 800 (first cohort), 120 equites > 5240

Legion in game: 1080 (9x120), 1280 (1x200), 1400 (1x120: general, equites, & bodyguard)
Legion in real: 1400x4 > 5600 (That should come very close to the real size of a historical reformed legion if you include the 305 extras like officers etc.)
Full stack in game: between 2480 (+9x120) and 2750 (+9x150)
Full stack in real: between 9920 and 11000
Full stack with max artillery in game: between 2000 (+5x120, +4x25) and 2250 (+5x150, +4x25)
Full stack with max artillery in real: between 8000 and 9000

General Army (non-Latin)
Army in game:1500 (10x150), 1650 (1x150: general & bodyguard)
Army in real: 1650x4 > 6600
Full stack in game: 3000 (+9x150)
Full stack in real: 12000
Full stack with max artillery in game: 2500 (+5x150, +4x25)
Full stack with max artillery in real: 10000

This pack will say even more. (Just put the file in your data folder & tick it in the launcher along with the other 5 AE mod files)
I made it with the intention to use at medium unit size, but large unit size will give you a 1/2 ratio with a real army instead of 1/4 with medium. I don't like the path pathfinding issues, though, that come with the bigger unit sizes, that is why I prefer it medium size.

Anyway, I have tested it with several battles and I'm quite happy with the results. Test it and leave some feedback. I did not do any price or auto-generate adjustments yet, have not looked into chariots & elephants unit sizes yet either, but for the rest it gives you the idea. If you guys from AE are not interested in this, maybe I'll go for a submod myself.

Cheers!

[popovic]

Could you just briefly describe what you did in that pack?

[Viking1978]

I will give it a shot. I have been working on a system that represents legions as they were historically while keeping the possibility to represent at least 10000 men per stack. So, a stack does not only represent a legion, but an entire army, including auxiliary or allied units. That is not easy, as during the years of legion got organised a bit differently. More info on that in the above post. Anyway, I mainly changed unit sizes, added some unit caps, etc.

But as I did not want to simplify much, there were a few things to consider and that's the part that is a bit less brief:

- What is the ideal scale to represent this legion and have a game that is playable without pathfinding issues, lagging, etc?
1/4 of the real amount of soldiers, possibly 1/2 but then you may have pathfinding issues for the larger units and lagging. However, as it happens medium unit size is just half of ultra unit size, so we can have both for the same work and a player can still choose. Let me be clear, I prefer the scale of 1/4, which means that at medium size a historically 4500 men legion will have 10 units with in total 1125 men in which every unit is ¼ and proportional to its historical size. A later kind of legion that was larger and stronger had around 5600 men (represented in the game as 1400 men) consisting of 480 men cohorts (scaled to 120) and a first cohort of 800 (scaled to 200).

Historically regular legions of the same period always had a similar shape, a certain amount of units. Some things can be done to guide the shape of the AI recruiting. I don't mind that an army has 8 instead of 10 regular cohorts, but I would mind if it had 12 if that can be helped. This can be managed by caps and CAI tweaking. I'm not sure yet what all the possibilities are here, but I will look into that later. (Auxiliaries don't cause any problems as they were independent units, not really belonging to a legion and were freely exchanged, assisting one legion there and another legion there)

- What about cavalry and the general bodyguard?
First of all, I do not want to split up cavalry, creating small units if it is not necessary, the way they do it in the vanilla game. I would like a full stack to be able to represent at least 10000 men, (2500 men in-game). Secondly, the regular cavalry in a legion was very small: 300 men in early legions, gradually lowered to 120 horsemen in later legions. It would be possible to represent the first one as a unit of 75, but how about a unit of 30, doesn't that just take up a slot where you could have something better? And what are those 30 going to do anyway? Will I make it a 75 men unit as well? That would mess up all of the historical accuracy I so badly wish to present completely. I prefer to make both part of a bigger bodyguard for the general. Bodyguards varied depending on the general anyway as they were private units, they paid them themselves according to their need and personal funds. The AI is already so reckless with their general unit that I do not like the idea of a small bodyguard anyway (unless it is for players only and temporarily in the case that the option of splitting armies ever gets implemented). Anyway, concerning cavalry, the Roman legions depended on other sources for that, namely independent units of allied and auxiliary units.

- How were these allies & auxiliary units organised?
The size of an auxiliary was the same size as a normal cohort. Historically there were bigger ones also, even mixed auxiliaries (containing infantry and cavalry), but they cannot be represented in the game anyway. As for a regular auxiliary cohort, it was the same size as a regular legionary cohort: 480 men, represented in-game as 120 men. So, a cavalry unit is the same size as an infantry unit, unlike in vanilla. The same with missile units, as e.g. some velites historically had the same size as the hastati & principes or some Cretan archers cohort had the same amount of troops as any cohort of a regular legion apart from a first cohort. So, why change them into smaller units the way vanilla did in Rome II? You can just have fewer units in your army when you need less archers like in Attila, and why not do the same for cavalry then?

- What about armies of other factions?
I started by looking at the Roman legions, mainly because they are complex and because I wanted to get them right for sure. We know most about them (not even that much) and not a lot about all the other factions, which were in most cases probably less organised anyway. We also know that the Romans were often outnumbered and still rarely got defeated. Although Caesar's stories will be undoubtedly exaggerated, it seems fair to make other cultures' army units a bit bigger. So all their units (infantry, cavalry and missile) will have 600 men (represented in the game as 150), 20% more than the 480 men cohorts of the later legions (120 per unit in-game) and around 35% more then the earlier units (100 per unit in-game). Maybe some other cultures that had some more military organisation also need some unit size differentiation (Carthage comes to mind), but I have to look into that still.

- If you change all these things, don't you need to change unit prices and other things also?
More horses should mean higher prices also. Dismounted these units are the same as normal infantry, which can be handy for rough terrain or during sieges, but horses were expensive also.
True in most cases. However, some cultures (e.g. Parthia or nomadic factions) highly depend on horsemen and therefore some further differentiation should be in order. Probably they had more horses also, at least more second choice horses, and prices may have been different from the west. In nomadic tribes life was all about horses, everybody had a horse there, not always a good one, but at least they had one.

[popovic]

Thank, that looks interesting. I`ll try out that submod.

[Julio-Claudian]

Cool idea. Was hoping for something like this. Though I struggle with units being below 240 men, I like having 10000 man stacks lol. I just multiplied everything by 1.25, so a standard unit is 300 men, cavalry 150 and Triarii etc. are 375, though I think I'll make Trarii 300 again. So four units of Hastati, four units of Principes and three of Triarii plus two Equite units and some Velites is practically what size a legion would have been irl. That's like 15-18 units and I always do 40 unit armies so there's room for two legions and auxiliaries, consular army size.

I wonder whether this messes with balance though. Doesn't seem to to me.


I wish there was a way to show a difference between manipular and cohort organisation.

[Willhelm123]

We've toyed with stuff like this before and though it is very cool it simply isn't balanced and ultimately that has to come first. It would be a fantastic submod though, and we hope people can modify ancient empires to be used to visually display historical legions or ancient armies. This is the mod you should use to make machinimas.

[Viking1978]

We've toyed with stuff like this before and though it is very cool it simply isn't balanced and ultimately that has to come first. It would be a fantastic submod though, and we hope people can modify ancient empires to be used to visually display historical legions or ancient armies. This is the mod you should use to make machinimas.

Could you be a bit more specific about which part that you mean is not balanced?

[Viking1978]

Cool idea. Was hoping for something like this. Though I struggle with units being below 240 men, I like having 10000 man stacks lol. I just multiplied everything by 1.25, so a standard unit is 300 men, cavalry 150 and Triarii etc. are 375, though I think I'll make Trarii 300 again. So four units of Hastati, four units of Principes and three of Triarii plus two Equite units and some Velites is practically what size a legion would have been irl. That's like 15-18 units and I always do 40 unit armies so there's room for two legions and auxiliaries, consular army size.

I wonder whether this messes with balance though. Doesn't seem to to me.


I wish there was a way to show a difference between manipular and cohort organisation.

Just play this mod with ultra unit sizes... You will have stacks up to 6000 for non-latin factions. The reformed legions will also have units of 240 and a first cohort of 400 and in campaign (when that comes out you will manage to get 5500 in a stack if you buy mercenaries of 300 instead of auxiliaries of 240 to back up the legion. In the last case you will have stacks up to 5000 men. You will have the double of that (so up to 12000) if you use large armies. If you play with the Romans you could field 2 legions, even 3 if you make them cheaper. I am going to try that out against Parthia now and listen to the thunder^^

EDIT: Sorry, man! Nothing for me these 10000 men battles. The battlefield is too small for horses to outflank properly, too much lagging also. But try it in medium unit settings and you will see it's fun!