I see what the OP is saying. But I remember that guys oftentimes keep maturing into their 30s. Westbrook right now is 27. Keep in mind that Jordan didn't win his fist championship until age 30 (if I remember correctly... someone correct me if I'm wrong). Until then he was seen as an explosive scorer but not necessarily a great team player, with a Chicago team that could never get past the Pistons.
Last night the Thunder started the game playing team ball on both offense and defense, but then got punched in the mouth and fell back into bad habits. Barkley pointed this out immediately after the game, and I think Donovan intimated it in his postgame press conference. Maybe with a little more age and maturity guys like Westbrook have the focus and calmness to break that tendency, and refocus the team. That's not easy, but the point is that even at age 27 you still might not be looking at a finished product.