Yeah. I didn't mention i've increased unrest everywhere too so you *need* those garrison units to stop revolts. I'm basically aiming at trying to make it difficult to expand your empire even if the AI wasn't there as opposed to having huge numbers of AI armies, as I get a bit bored with that. Not finished yet though so i may find you're right.

Regardless of the upkeep issue though I think setting your costs purely to manipulate the AI into producing good armies is worth thinking about. Have a very simple formula to start e.g 200 per level of barracks, and then test and tweak it until the AI factions are producing the kind of armies you want them to have.