quote Dave Pottinger, Interview

The goal for Age 3 was to slap 300 to 400 units on the screen at one time, which is a big step up from Age of Mythology. That's a pretty big number, so we've spent a ton of time optimizing the game all over the place to make that happen. Yes, there is still a population cap. Our goal, of course, is to have as few folks as possible hit the pop cap during normal gameplay. It's there to prevent the edge cases from creating a bad gameplay experience.