City-Spam is alive and well in EWOM. Even though I don't like the expansionist strategy, I am quite picky about where to put a city, but the AI plops a city absolutely anywhere they can in the shortest amount of time possible. Any free resource on the map whether it's a crummy elemental shard or an extra food is deserving of a city in their opinion. The worst part of it is they don't optimize the city locations to cover multiple resources, they often have 2 or 3 cities covering a few resources that could have been covered by a single city placed properly.
Besides the obvious of the AI being dumb which makes it less enjoyable to play against, the fallout from the situation is when I ultimately end up taking their crummy little towns and don't know what to do with them. You can't raze cities in this game. Why can't you raze cities? Why?? In any other game like civilization I would starve them out then build my own empire of perfection, here in EWOM I leave them empty and hope a roaming monster comes along sooner rather than later so I can get rid of the annoyances.
The idea is simple, Prestige from your improvements and characters make a global sum that is used to determine your max cities/city size.
Example:
City Lvl 1: 10 Prestige
City Lvl 2: 20 Prestige
City Lvl 3: 30 Prestige
City Lvl 4: 40 Prestige
As far as the numbers themselves go, that's just a balancing issue. The first city is either exempt on lvl 1, or you can just give your sovereign a base prestige of 10 to start with. In the long run this forces you to have more heroes (or governors) before you can build extra cities, and gives a better use for high charisma characters. it makes sense that your empire would need greater prestige before people would start flocking to it like crazy.
This would also give more flexibility in the way of resources, as far as there being too much or not enough. The resources themselves are a concern that must be weighed with the actual size of an empire you can support.