There is a major game breaking bug. The CAI for various factions will act stupidly for some faction in the game by disbanding armies or not rebuilding and resurrecting dead navies and armies. It is completely random. Playing the game with fow or just looking at save parser files shows factions that have tons of income but no armies mid game. It is beyond game breaking.

There needs to make a force value for all AI factions to take absolute priority on making the current armies = total allowed armies and navies for imperium level. Then force the ai to build full stacks or have at least 60-70% of their total max force. I noticed on my play through that WRE for example had all their stacks destroyed and now they just have 1 navy with 4 vessels for the past 30 turns. they are not doing anything. Another playthourgh ERE didn't do anything and disbanded some armies. Also i have seen factions disbanding buildings to tier 1 even if they are the same culture group. Another modder on Steam MINOS noticed the same issue but he moved on to Warhammer. Please, for the communities sake, save this game from this game breaking bug.