I would throw Davis in that category as well even though his team is not winning as much. Davis is leading the league in scoring and shooting 3 less shots a game than Westbrook and leading the league in blocks. Harden is at 3 less points per game than Westbrook but shooting 5 less shots a game and getting more assists. But those three players if they are taken off their teams are instantly one of if not the worst team in the NBA.
I think Westbrook efficiency will start to taper off after the all star break or his body will break down a bit, same with Harden. They are just doing so much for their teams. Westbrook is already taking 24 shots a game on 42% shooting. If that number dips below 40% he should not win, that is just chucking, unless his team is in the top 4. But I think Utah will be the 4 seed by the end of the year and stay up there bumping OKC down to 6th where I think they might stay unless Westbrook misses a good chunk of time for injury.
Although as I was typing this I decided to look up distance traveled so far this season by players and Westbrook is 20th, Davis is 19th, and Harden is like 40th. Hayward is really high despite playing less minutes. He is normally top three but is 8th this season. Lavine, Barnes and McCullum are top 3. Although those are per game. Hayward doesnt make top 50 for totals because of games missed and Westbrook is #4. Davis and Harden stay the same.