If nothing else he was able to make those 3 players co-exist. More than I can say for James, Dwight and Lawson at the moment. His only reason for getting fired was because he didn't win with players injured. Not sure how you remember his teams, but they were always very good. I think our roster shows that talent doesn't always translate to wins. He made it look easy.
I don't think he "made" them co-exist as much as they came in around the same time and grew up together. It wasn't a situation like LeBron/Wade/Bosh where each were established franchise players prior to joining forces. And I remember his teams fine but I also remember the bad judgments Brooks made too (e.g. overplaying Perkins, over reliance on Westbrook and Durant to carry the offense, etc.). You can't fault Brooks for his team getting injured and thereby not winning. But you know whose team was also oft injured and kept winning? Thibs.