How do spearmen work?

[meerkatology]

most spearmen like triarri / hoplites have a sword for their secondary weapon, which usually does equal or slightly more dmg than the spear.

spears suffer a -dmg against infantry so their swords are usually much better against infantry but the AI doesnt really like to use them, seems that only the very front of their units will sometimes use the sword but most of them are in spearmode even against infantry. do their spears have a longer range that the 2nd line can still attack? otherwise isn't it always better to have them in sword mode against other infantry ? it kind of defeats the purpose of hoplites and such but i dont see any advantage of them using spears at all against other infantry.

same as 2ndary weapons on cavalry espeically ones with armor piercing axes, the AI never uses 2ndary weapons on thier cavalry even tho they are always better for melee

[Alavaria]

Actually, it seems a bunch of secondary weapons are worse for the lancers, due to having the same attack stats (hit about the same) but less lethality.

type dacian xystophoroi cavalry
dictionary dacian_xystophoroi_cavalry
category cavalry
class heavy
voice_type Heavy_1
soldier xystophoroi, 30, 0, 1
officer draco_standard
officer east_heavy_standard
mount half armoured horse
attributes sea_faring, hide_forest, very_hardy
formation 1.5, 4, 3, 6, 4, square, wedge
stat_health 1, 11
stat_pri 11, 42, no, 0, 0, melee, blade, piercing, spear, 25, 0.684
stat_pri_attr no
stat_sec 12, 35, no, 0, 0, melee, blade, slashing, sword, 25, 0.468
stat_sec_attr no
stat_pri_armour 23, 12, 0, metal
stat_sec_armour 3, 1, flesh
stat_heat 2
stat_ground -1, -3, -7, 1
stat_mental 18, disciplined, highly_trained
stat_charge_dist 58
stat_fire_delay 0
stat_food 60, 300
stat_cost 1, 416, 195, 22, 31, 52
ownership dacia, thrace

For example here, you have 1 less attack, but a hit kills 46.8% of the time compared to 68.4% of the time. This can be important if your horse is coming from behind, as usually your attack value is much higher than defence (you'll hit a lot) so having your hits kill more frequently is important.

Obviously you want to check if your unit has an armor piercing secondary (unit information in game won't show it), or look at their weapon which hopefully matches.

spears suffer a -dmg against infantry so their swords are usually much better against infantry but the AI doesnt really like to use them, seems that only the very front of their units will sometimes use the sword but most of them are in spearmode even against infantry. do their spears have a longer range that the 2nd line can still attack? otherwise isn't it always better to have them in sword mode against other infantry ? it kind of defeats the purpose of hoplites and such but i dont see any advantage of them using spears at all against other infantry.

If you have them sitting on guard mode, they tend to not get tired, whereas it seems you can't get them to use swords while staying in formation.

In some cases having them hold their formation (especially on Guard mode), even if they use spears, will allow them to fare better than you ordering them to attack with alt-weapons and brawl with their swords. This is because if they tire themselves out, they will start to fight worse.

do their spears have a longer range that the 2nd line can still attack?

No.

It seems you're either using a pike (attacking in melee at a distance) or you're pointblank, using a spear, shortsword, longsword, axe, knife etc

[meerkatology]

agree with rest of your post, but i dont think lethality works like you said.

everyone unit has the same actual lethality in this game when balanced out for their animation type. i remember the devs saying that different lethality values was meerly to balance out different attack animations.

this can be tested easily as well. for example, the elite thraiken rhomphaiai has 2 weapon modes, the first one similar to a spear 19 dmg non AP, second weap is 19 dmg+ap, with a different animation. the secondary weapon actaully has almost 1.0 lethality, while the first one has around 0.5.

if you take it literally even without the AP the secondary should be about 2 times more powerful, but this is not the case during my tests.
you can easily test it too, just remove the AP attribute on the secondary and fight them 1v1 vs. eachother, one of them using the primary and the other using the secondary, i think you will come out close to even though the secondary has so much more lethality displayed

[CatoTheYounger]

Triarii areg great to use in guard mode to hold the line. Like mentioned they don't tire in formation. They are good to take off guard mode in two scenario's. One is when attacking cav they do more damage and shred the cav units. The other is late in a battle when the other army is completely exhausted and yours is still fresh you take them out of guard mode and they start to slaughter. For the Romans it's best to wait for the right moment to push forward.

As for the swords they generaly start to come out against infantry when you undo guard mode. Seems to be gradual. Triatii are my faorite units as i always prefer defense over offense. Just my taste.