That's why IU gotta hire someone that's been there and done that. It was Archie's first time coaching a star player, even though Romeo was calm and fairly a nice kid, he didn't know how to handle the whole situation. My guess is he didn't really do anything to manage players' egos and to guide players to the positive direction. Also, he always picked quiet, introverted kids as team captains and failed to recruit potential leaders.
His style probably only works in mid major tier where players he can recruit are usually lacking skills and raw talents so they play with a chip on their shoulders and play physically/aggressively to earn playing time.