i think it would be cool if one of the wandering heroes in the game some how got to a certain level(maybe they gain levels automatically by fighting stuff and whatnot) and no one hired them, AND somehow gained a certain amount of units and attacked a factions city and won.  they would become like a sovereign and found a new faction in that settlement.  then they would start to expand. they wouldn't have access to any magic but could utilize standard tech and build armies. it would go along way in my opinion to making the world feel more alive.