There are two things to consider. First, Allen is iron, and Wade is the best, stable and comprehensive in SG position. If it is expensive, Kobe is better than Allen. Even if Kobe is more aggressive, he will average 15+ per game. In addition to scoring, Allen's contribution is a little less.
The substitute is short, and neither Anderson nor McGrady can defend. Curry is also relatively iron, PG is ok, and playing SG can be depressing. Nick young, basic salary Harden and Roy are all good substitutes.
It is not good to substitute for PF. Drivers shoot a lot and rebound well, but they are often exhausted. Boozer and Odom of 800+ can ensure that the PF position will not drop after the driver leaves.