Brantley looks pretty bad to me. The guy looks like he cant do much in the half-court other than dribble into post-ups.
I think he's trying to learn his role and be a ball mover. I don't think his abilities are that limited, but he was playing on the ball and he doesn't know how to make reads and decisions yet. On one play, he wanted to feed Juwan Morgan in the post, but he wasn't able to get the angle, so he forced up a last-second fade-away that missed badly.