Westbrook, Harden and Durant are all average (don't really help or hurt their team defensively when they come in) NBA defenders as their advanced stats indicate. Harden certainly has been horrible in the past, but was actually pretty decent this past year with a positive 1.0 defensive box plus minus.

Durant doesn't need the ball in his hands as much as the other two, but I definitely agree that both Harden and Westbrook need the ball in their hands and are shoot first guys.