I think the thing with Jaylen is that he has a weird role for a star. He looks wildly inconsistent within games, but is quite consistent in his overall output game to game. I have never understood how the C's use him. He often goes off for a quarter, takes a breather, then comes back and barely touches the ball the next shift.
I think a lot of fans identify his handle as his main problem. To me, its that he has pretty poor balance for an athlete that is so advanced otherwise, and inconsistent footwork, and that affects his ball control. These are fixable things. He isn't very far from being completely unguardable.