Yup, it was a bug that (to my knowledge) was never patched out of the game. I didn’t discover until much later that there was a mod that rectified it. It only affected truly gigantic cities, but by late-game especially if you were playing as someone like Egypt it was easy to have a bunch of those. Petra and its ilk were always going to be a one-horse town, but Alexandria, Thebes, Tyre, Sidon, etc… all wallowing in excess squalor to the point where I had to station full peasant armies in each to keep them content.

I never thought about mass-recruiting as population control though, that’s clever.