Obviously we want our best 3 point shooters shooting the most 3's.
Your comparison to Carlino doesn't hold water since Emery didn't play PG and dominate the ball and was also way more efficient shooting the ball.
Emery is a much better player than you give him credit for. He played two years as an underclassmen with decent efficiency and good defense....all while giving 100% on the court.
He would have helped the team big time this year if his head was right.