We've seen the Rockets for a few games, and the dynamic Westbrook and Harden will probably have. This is Harden's team, but given the fact Westbrook isn't a great catch and shoot player, it would make more sense for him to initiate the offense, penetrate and dish it out to Harden.
Coach D'Antoni said they intend to use Westbrook the best way possible - 6 seconds or less. Russ is so fast with the ball D'Antoni shaved one second off his system and gave Russ free reign in transition. But the half-court is Harden's game. That means Westbrook will have to improve in two areas he wasn't so stellar in Oklahoma. Off ball movement and shooting.
Scottie Pippen knows a thing or two about transitioning after your prime years are behind you. The difference being Scottie was never the no.1 option and so dominant in ball possession as Westbrook. But both players moved to Houston and were expected to accept a new role and style of play. (via The Jump):
"I dealt with that situation going to Houston the year I went there. They wanted me to be a three-point shooter and watch Hakeem and Charles post up. I was never familiar and comfortable playing that role of being a spot-up three-point shooter. That was part of the reason I didn't fit in with the Houston Rockets."
Scottie believes the two can work together and that Westbrook can fit in better than he did back in the day. But he made it very clear; it is Westbrook that will have to do most of the fitting in. He is the one that has to change the nature of his game and the role he will be playing in.