As things are now you can build Pioneers and make as many size 10 citys as you want as long as they are not in the min distance from another city. In the games I've played the AI is very good at this, in fact I've seen lone Pioneers running through my lands during wars the make new cities. I've been thinking about a way to make where and when cities are built more important. My thought is to make new cities take one food. The way this would work is: You leader would found your first city and give you -1 food, but you should have a farm near by to fix this, Pioneers would not be able to build new cities with out 1 or more food. This increases the value of food and forces recon to find new food to expand. Players and the AI will have to decide between having large cities or many cities.