Maybe I am grasping here, but I see this hire as very good for JJ. Remember, Billy has had Lee Humphrey on his team for the last 4 years - he understands (I would assume) the benefit of an excellent spot up shooter to loosen the things inside (at UF - for Horford; at Orlando - for Dwight Howard).
Maybe its a stretch, and I know the NBA game is completely different from the College one, but it seems the same principles apply.