Coaching isn't overrated, but it's not as nuanced as a lot of people believe. First and foremost, like any high-positioned leadership, it's really about having a vision, encompassing a philosophy and managing egos. Then you tweaking the pieces in the best positions to be successful for all, without damaging the overall culture. The day-to-day stuff (in this situation...on court...is mostly handled by the players).
Shaq is only partially right...minimally right. Teams can win without a great coach, or a coach that doesn't do anything. But the culture of the team has to be right, with everyone on the same page. And just because you're a great coach, doesn't necessarily mean that you're going to win. In the end, the coach can do their job, but it's still up to the players to do their part - which is most of the heavy lifting.
But in the NBA, it's mainly a coach having the players that fit their vision and are able to execute with minimum involvement. You can also be a great coach, have everything needed, but lose because you don't have the personnel that fits.
