Acc. Gibbon, Edward: The Decline And Fall Of The Roman Empire
Stickler, Timo : Aetius
McDowall : Late Roman Infantryman/cavalryman
regional field armies. At least 1 in every Diocese: Galliae, Africa, Italia, Hispania, Illyricum.
CAUTION
One regional field army may have more than one legion!
The legions are garrisoned in cities. A mobile regional field army is alway a combination of many legions. But due to money problems
you don't have the possibility to include lots of legions, and I think this is also more or less historical.
As I explained before (with hist. sources): the basic was the Auxilia Palatinae
An example for any province: (and please: THIS is only an example for a regional field army in the diocese X!!)
Legio XY
1 General
2 Auxilia Palatinae (or 0 or 3)
or Pseudo Comitatenses
1 Auxilia Illyriana (0 or 2)
4 Comitatenses (or 3)
2 Exculatores (or 1)
1 Sagitarii (or 2)
1 Equites Auxilia or 1 Equites Illyria or both
if needed
1 Equites Stablesiani or Equites Scutarii as additionel guard of the general
it is absolutely Ok if you use also
1 unit of Equites Promoti
Legio Auxilia Palatinae
1 General
4 Auxilia Palatinae
+different kinds of Foederatii
+Illyrians Soldiers
+if needed Sagitarii
+if needed 1-2 local cavalry
mounted vexilationes
mobile task force
can used for fighting with the legion or can (if time is too short) fight alone.
The mounted legion should garrisoned seperatly of course at a central place of the Diocese.
1 General
2 Equites Promotii
2 Equites Sagitarii (or 2 units of mounted huns, or Sarmatians. Units can be mixed of course)
1 roman Equites Armaturae
1-2 shock cavalry: can be Foederati Unit or a roman unit like Cataphratii or Clibinarii
+ if needed some minor mounted troops like Equites Auxilia or Equites Dalmatae
+
1 unit of Equites stablesiani or scutarii as additional guard for the general
If you play a long time,due to long wars and due to the money problem you
will face the same problems as Aetius. The troops will be smaller and smaller.
So you will automaticly use more and more foederati. That's natures law.
This example was an example for a regional field army.
But the romans had also a
central field army:
The Palatinae:
So if possible form 2 Palatinae legions:
Legio
Ioviani
1 General (Emperor/Mag. Officiorum)
1-3 Auxilia Palatinae
2-4 Comitatenses Palatinae
+if needed Archers
+so much as you want (2-4)
Scholae Cavalry
+good foederati units for the flanks
Legio
Herculiani
see:
Legio Ioviani
Normally at the beginning of the game you don't have enough money to make or create such a central field army. But try to transfer at the beginning so much units you can to the central field army. But these units should be the best ones.
Later in the game (430-440 or later) you can mix these units with the normal comitatenses units of the regular regional field armies.
In one of my sources I can read that these units of the Legio Palatinae were only used in case of emergency. In another source I can read that this central field army were the fire-workers and also partially used as fireworkers.
The Auxilia Palatinae had also to do sometimes special jobs in the enemies land, or to sabotage. So, I think it is absolutely OK to use these legions as you want. Feel free!
Historically: In the later periods more and more "barbarians" were transfered to the central field army. And lots of mounted Foederati troops. Odovacer, for example, was an officer (a barbarian one) in such a mobile central field army. And in this army there were nearly only germans.
Normally the regional field army stays always in the given Diocese. And the central field army (the 2 legions) is the army which is walking arround.
But in the dark age.... what is normal???
So feel free to do what you want: You are the Augustus.