I create cities all the time, when I generate a new map.
But to be serious, the above is very vague. What do you mean when you say create a city. If you mean build up an empty section of fields into yer own handmade city, absolutely, and it will take exactly as long as you would expect it to take one man to make a whole city.
Or perhaps do you mean create a living area full of NPC’s? If that’s the Case, Faction Camps sounds like the thing you are closest to wanting.