maybe it comes down to how the team is. A lot of question marks on offense Butch might go with the more established player. Or if he doesn't trust the O-line maybe he goes the more mobile player. maybe our skill players are so good that he goes with whoever gets them the ball better, more of a game manager instead of someone who has to win the games themselves.
I also wonder if off the field issues might determine things, if it is a 50/50 split or only a slight favorite. Get in trouble, get benched, grades aren't up to snuff, get benched, miss a meeting get benched. a lot of things will go into it.