JMO but I think if he goes to Stanford he can most likely stay at the DE position. If he goes to LSU he'll end up on the O-Line after his RS year, maybe in his 2nd year. If he comes to Tennessee it will probably be the same thing as LSU. If he wants to play in the NFL his best chance will be on the O-Line.
I really believe people are telling him that his future in the NFL will be on the O-Line but family and a few friends are making him believe he can play DE. I just don't think he's fast or quick enough. The need for fast and quick DE's in the NFL is recognized by every team in the league.