Moon is fine the way he is, not every player needs to become a great offensive player to be a factor on the floor. If Moon didnt improve that much in the offseason he'd still be a very good role player for any team.
All he has to work on IMO is his shooting and MAYBE one dribble drive move off the catch. He is never going to be a major option on the floor, he'll be playing the Finley/Bowen type role on offence which is catch and shoot, and if a defender comes at you hard then drive it or pull up. Nothing fancy.
Having JO behind him will show how good of a defensive player he is this upcoming season IMO. He wont have to sag off guys anymore knowing theres no interior defence behind him. Jamario is gonna be sick next year