If KO's putting up 17-20ppg in a support role and hitting 40% from 3, he's not coming off the bench. He's starting so he can stretch the floor for our best players and score off action with our best playmakers.
It's Sully's more iso and match-up dependent offensive game that's a better fit for the bench, a la Paul Millsap, Corliss Williamson, Rodney Rogers.