I have a problem when people start comparing Bradley to longer defenders like Cooper. Bradley legitimately has a chance to be one of the best defenders at his position in the NBA. However, a 6'2 defensive stopper simply isn't going to be as important as a Cooper or Bowen.
If Bradley were 2-3 inches taller, he could be a legendary defensive player due to his incredible athleticism and on-ball skills. Unfortunately, he's not taller, and while he might fill an important role for a contender at some point, he won't be an all-time great.