As it's primarily the barbarians that struggle the most with pop growth, I added a health bonus +4 for barbarian cultures only to the base governor's building, so they get an extra 2% growth and 20% happiness. The next level town I cut this in half, and for lvl 3 towns in half again. Seems to be working so far, but needs more testing.

I also worked out a less severe approach to bridling the AI's poor unit choices, without having to monkey about with costs and build times. I made recruiting low level units dependent on the presence of a blacksmith. For example, a level one town builds a barracks and trains militia. At level two, it upgrades the barracks and can train hastati. now in order to unlock militia for this lvl 3 barracks, it has to build a trader to unlock the balcksmith and then the blacksmith, then finally the upgraded milita. In the meantime, the only thing available to train tin town has been the hastati, so the army should be a nice mix. At level three barracks, hastati need the blacksmith to unlock them, and militia need the second level smith.

Peasants I tried to link to farms, such that you could only recruit them in a town with maxed out farming. I thought this would incentivise the AI to build pop growth, and punish the human who wants the cehap hug garrison with some extra squalor and teething pains along the way. Alas, I couldn't get it to start a campaign with those tags in place.

Frogg, if you want to check on the AI in your game, open RomeShell and type toggle_fow to show the map, then toggle_perfect_spy to make all factions omniscient (sp?) Hope this helps, I feel like I owe you any help I can give for all the electronic lives under my command that were saved by your guides.