army should consist units from Factions but if any other used that is also okay if there is lore context behind. (or just have fun)

for example: Rusty Nails stole machines from Unity
and now using them to defeat temples of Unity.

and in that context or any other to keep the fun element.

armies usually have one general or to be more specific small armies with army size + point limitations

if army has 250 points , and I can say some general unit has cost 100, its kinda pointless to have 2 generals and have firepower difference to your enemy

when you picked you army size , and units
its time to place on the map .. if you don't have map check out map creation

player can freely place units on his side