I do not support limiting city building.. it is as fair a strategy as the zerg is.. If i manage to build up a bigger empire that allows me to make elite troops that whoop on some ones butt.. then good on me...
however! the AI builds way to many cities just because it wants to link to resource with out considering growth of other cities.. this needs to be fixed..
there is a suggestion about tweaking the population and time it takes to make pioneers that may help with some of this.
I do think we need to find a happy medium between where we are right now and slowing making new cities a bit.. once suggestion that I think has merit is that like caravans each city can only create x pioneers (be it one or more), I think this and not allowing a city to make a pioneer until it reaches level x (2 to start) might also be a good way to go..
I also think that providing reasons to not make cities could also help this.. one suggestion (and I like this one) is specialized outposts. think of these as level 1 cities devoted to one task, military (please god we need forts), gold, metal, crystal and so on..
I can adapt to what ever comes along but forcing me to build less cities because I may gain an advantage if you do not is not an acceptable reason to limit my city building(unless of course your the AI that simply cant cope and even this disturbs me).
I hope what ever comes along has a toggle/slider so we can accommodate all styles of play.