I don't have an answer to any of this but am not sure about having such a high proportion of upkeep to build cost, e.g.
Quote Originally Posted by nikolai1962
So i made the cheapest garrison unit cost 600 with an upkeep of 300 as my baseline cost....
having played mods that had similar ratio, it soon became apparent as human player that it wasn't worth maintaining units that weren't immediately required for battle / essential garrison, so it was more economical to disband units not needed in back areas and rebuild later on front-line instead of moving them forward.

I can see how system would work between AI factions to produce desired army. But am worried that the human player may be more adept at avoiding the higher maintenance costs (as above) and hence add to the AI's disadvantage ?!