From what I have seen drummond gets in passing lanes and gets a lot of deflections in addition to blocking shots. I don't see hibbert do much besides stay near the basket and block a few shots per game of which a lot end up going out of bounds or back to the opposing team and aren't really that valuable. from a half court team defense perspective I might prefer drummond and clearly from a transition defense perspective I would take drummond as he will rarely ever get beat down the court by the opposing center. So I wouldn't say that Hibbert is a much better defender when you consider the overall half court defense and transition defense. Shot blocking he has an edge though. I think Hibbert would be more valuable to a bad or decent team to become good or very good because he is an offensive post presence that can open up outside shots. I think a good or very good team would want drummond because he can impact the game in just about every way without having the ball in his hands and compliments star guards and forwards extremely well.