Just a theory, maybe its cause of their weapon's, you didn't give them something op right?
Mine have a basic sword and broken mace and i usually find them together(and quite often), while the 3rd with the fancier mace i usually find with others(and a bit less)
I have 6. Played for several hours after I made them. All but 2 have shown up during that time. Literally, not once out of all that time have those two shown up once. That's beyond just random.
I don't think it has any effect. One of my NPCs has no weapon or cloths and shows up often on all levels. Order of creation may have something to do with it, but I really have no clue.
