The AI does have that script for # of units per city, which probably makes it such a stack builder. You would think that there would be scripts for all those improvements to ease that overload. I let the AI manage my cities from the start and it allocates population decently, but it still has all archers by 1000AD and now is working on horseback riding without any horses. Axemen...they don't have any city bonuses, pfft. The autoplay is not good at all on high difficulty unless you are far ahead of everyone.