I've played many of the factions out there and notice none have a leader. Why doesn't each faction have a unit that is the leader? I can see how it may affect gameplay but if it's used in a way that killing a leader doesn't mean victory for the opponent, then I don't know why no one has a leader. The leader unit would be one that you could only have one of at a time. It could also add a little side game within the game as you need to protect your leader because if he/she is killed, they are gone forever and maybe the replacement leader could be the unit with the most kills at any given time in the game. I currently designate my own leader, for example I use the Shaman in Indians and Sorceress in Dark Magic. I only create one Shaman in the game if I use Indians and don't create a sorceress in Dark Magic because you start with one. It would be nice to see a Chief in the Indians, the big feather hat on the head and all that.
