Factions don’t normally appear in the way I personally think they should. Ala; Tribes(not the game).
Factions are as far as I can tell, not a specific kind of group. Such as Walking Dead. Each “group” is like a tribe and we don’t seem to have this in our game. NPCs have a listing of factions that each NPC seems to be apart of. But makes no sense to me at all…perhaps because it really makes no sense at all? xD
Every NPC should be autonomous and be given an open space in their character background. This would make it a unaffiliated NPC by default and any grouping of NPCs should have a unique group/tribe moniker added to them to affiliate them to a specific group/tribe.
Joe Shmoe NPC
Tribe:blank by default as no group; name given to associate with a tribe/group/faction (this line would be hidden unless told to player).