Westbrook, Lebron, and AD. All three players need the ball to be effective with their game.
For this to work, one of them is going to have to become the 3rd wheel. If AD would play the 5, that would probably work best for them. But it's well known he hates the 5. So not sure he would be willing to do that.
The Nets had a similar type problem going in when they acquired Harden. Harden did adjust his game to be more of the point/distributor. But we never really got to see how the chemistry would work when all 3 of them were on the court very often. Usually one or two of them were out with injuries.
Westbrook is a stat filler. Amazing talent, but has very rarely in his career been the guy to take his team to the next level. Or at least the level they should be at with his skill set. Will be interesting to see how this plays out.
This sort of thing reminds me of what the Lakers tried to do with Kobe and Gasol that one year. They brought in Dwight Howard in his prime and Nash to run the point. They immediately became heavy favorites to win the Title before the season started. Then that thing fell flat on its face, fast. I don't think this will be a disaster (although I hope). But I do predict this won't go as well as our friend The Green Fruit thinks it will.
Westbrook will serve as more of a distributor. He also can provide some playmaking when LeBron is out of the game.
The point is to let LeBron be able to play off the ball more than he has in recent years. LeBron can be effective in so many ways, and doesn't "need" the ball to be effective with his game.
I would expect AD to be playing the 5 more this year, though he will likely still like to drift out to the three-point line even if he is the de facto 5 on the court.
Westbrook has elevated teams before, most notably the OKC squad in the year immediately after KD's all-time weak move of going to Golden State.
Comparing Nash/Kobe/Howard to this trio doesn't quite work. This is a much better Big 3, with much more compatible parts. Only question is if they can stay healthy, with AD being the biggest question mark. LeBron has aged as gracefully as about any all-time great to this point, though he is more prone to injury now (which is not saying much, because is remarkably durable).
Get some shooters, stay healthy, this team will have a great shot to win it all. Definitely the favorites in the West.