As I was working on a mechanism for transformable CC's (into carts and back into a building) for nomadic civs some time ago (not finished yet), I wondered what the benefit would be of having such a mobile CC. Currently expansion can be done anywhere as long as you have the resources, plus can get the construction work done (which means units have to go there). One thing that could bring interesting gameplay benefits to nomadic civs is if they could indeed set up shop wherever they want (that is, wherever they could get their CC cart), while other civs could only build a CC not too far away from another, earlier built CC. Thus, there is a clear maximum for distances between CC. I can see some issues with my idea, the most important one is that some maps may limit options for expansion (think of the islands maps). Introducing a max distance could mean there is no suitable location, severely limiting regular civs. As an alternative, giving nomadic civs a similar benefit would be to do away with territory restrictions in general or lower their mobile CC cost (facilitating rapid expansion).