He has some skill and he has good handle. otherwise we wouldn't be talking about him as an offense-creator. He's better offensive creator than Huerter for example. The question is - can he be efficient enough to be primary or secondary offensive creator when he's lacking the elite athleticism and wiggle? IMO he needs not just good offensive creation, he needs to be close to elite. Good doesn't do it. Hood was damn near elite as a PnR scorer and on ISOs/postups... and it still wasn't enough. If offensive creation is all he does, he needs to be elite at it, not just good.
I dunno if he needs to be THE GUY who creates offense in our system where DMitch will have the ball is his hand a tonne and Jingle will also have the ball is his hand a tonne, and we're playing European ball where the ball is moving all the time. We do have DMitch if the offense stagnate and he's elite at creating offense.
If you pair JRob with DMitch, DMitch will have the ball in his hand a lot more than JRob, probably 70/30. JRob just needs to be able to knock down open 3's when called upon and take over some ball handling responsibility when needed.
Also at #21, you're not gonna get someone being 'elite' at many things... JRob is sufficiently quick and shifty, has good size for the combo guard position and he can knock down open 3's at 40%+ rate... to me that is more than you can ask for with the #21 pick.