Only peacemongers can allow themselves to have huge cities that grow much over the tile cap of a city. Warmongers have to struggle with multiple
modifiers as well as they rather resort to cheap ways of keeping the population happy, which means for most of the game getting it from duly upgraded
resources and civics. This means a two already needed buildings: market and forge for majority of the game.
Temples and similar cost a lot of
per each
they provide and you'd rather have your cities producing units instead. The
slider costs you a lot of
and it's more and less a waste, since you are not running for the cultural victory anyway.
So in the end result warmongers should resort to medium sized productive cities, while leaving full grown towns and villages that you happen to conquer to provide additional gold. It's a kind of a self regulating system: the further you expand, the more
you need and the later in the game there is and the more villages and towns and the less cottages and hamlets you find.
There is another quirk: before workshops begin to be effective a city that is surrounded by grasslands, flood plains, food resources and with few or no tiles that produce anything else than food, cottages might be a way to stop that city from constantly overgrowing. You may choose to turn the city into a small GP farm, but it depends weather you're philosophical or financial.
If you are financial cottages next to rivers and hamlets deliver 3
. This is a nice kick-off advantage. It doesn't count much in the later game, but it can fill an early budgetary gap. If you are philosophical, a city running 4 specialists(forge+library+temple) will spit GP at an decent rate as for end classical-early medieval age, while cottages are less attractive. (BTW I don't remember weather there is a PHI/FIN leader or is it one of the "forbidden" combos)If you have Parthenon, that might influence the decision also.
The problem is that before caste system you actually have to construct buildings to allow any specialists to run in your cities, cottages don't require it. Its not easy to equip an unproductive city with all those buildings.