There are few power forwards who I'd give the ball to for one possession on offense over New York's No. 1. That beings said, there are many power forwards I'd want guarding the ball for one possession on defense.
The problem, or prize, depending on how you look at it, for Amar'e is that he's never been in a system where defense was necessary, so his man-to-man is more like man-to-basket. His defensive win shares, the amount of wins contributed by a player due to his defense, isn't close to the top 50.