Something has to be done to encourage travel to other regions. Since tribes will be 100% self sufficient the only reason for them to travel is pvp raids really. Homesteaders will travel because they must trade with each other in order to survive but only in a small area around them I would assume. There is absolutely no reason I would ever need to travel from my home in the south the hills in the north, unless they had some resource or technology I can not obtain where I come from. Hence I would make a journey through perilous territories in the hopes to forge a new weapon or obtain a new item like a torch to light my camp area. This game is going to become boring really quickly if they don't keep making us want to explore. Trade in the short run is all wonderful and everything but what if JoeBlow in the North DOES have a new technology that allows him to make torches that only the North people can make , well what would I trade to them that they can't already get in their own area?