Lairs don't appear to ever respawn. After a few dozen turns on even a large map with a lot of AI players the entire "player vs. the wild" concept disappears. A wildlands area might still exist if you can find it (they are too rare) but it will probably be on the other side of the map across 5 AI's territory. Lairs should be constantly respawning (much faster if they already are) and monsters from wildlands should eventually move out and start invading people and perhaps building more lairs as they go.

Monsters don't attack cities enough. In fact I've only ever had a monster attack a city a single time, and it was because I built that city right next to a rank 3 quest location, which I eventually ended up failing and releasing a swarm of fire elementals and worms, and one of them attacked my city (probably by accident because they had nowhere else to move). Maybe make this a difficulty option.

I think the intention was to have tiles with yields be "rare" so players only had a few cities, but as a city's influence spreads the outer edges become fertile and eligible for city building. This leads to a carpet of cities across the map. Dozens of cities built as close to each other as possible from one edge of the map to the other. If there's a penalty for this the AI doesn't understand or care about it.

Pretty much this game falls apart the longer you spend on a map, it starts off a lot of fun with all sorts of things to do and areas to explore, but then all the monsters are killed, the lairs destroyed, all the treasure is grabbed and the quests completed, and then quite honestly at that point I do not find the game fun anymore. I've yet to "complete" a map, I quit right about at the stage I'm talking about.