Perimeter 4 is a pretty well defined role in winning basketball in today's NBA and its one that goes further back than most people think with all the bemoaning of the demise of post play.
So Raef LaFrentz then?
No, no. Young LaFrentz played like a prototypical big, in particular on defense. He kind of just had the ability to shoot 3's, usually from spot up positions. Maybe a decent post game for a time, as well. Don't remember. Celtics LaFrentz was a super watered down version of that.
Kelly plays a lot like a guard, but he's a legitimate 7'0. He can handle and pass from all over the court it seems. He's a weak defender at present, unlike LaFrentz who was very solid to very good as a young player. I think Kelly offers a much more diversified and beneficial offensive game, though. His ability to create offense for himself and others isn't something Raef had, particularly from the perimeter