I don't think it is a given at all that he will fit in as a 4-3 DE either. Perry might turn out to be one of those guys who was a decent college player, but doesn't really fit anywhere in the pro game.
He is a fool if he doesn't commit himself heart, soul and body to the "hybrid" DL/LB that the Packers have been talking about for the up coming season. It could be what is best for him, a little of each but a lot of neither.