Westbrook and Harden played together since they were kids, they know how they play and they know their own styles as well, they are not worried about it so why should you be. Right now Westbrook knows that he is coming to hardens team and he won't be trying to be the alpha dog there for sure but even if he does their styles are super different from each other.
But this is different though, this is not the backyard basketball arena. So you can't compare them as kids and as NBA superstars right? As NBA fans of course we can give our own analysis because we have witnessed how they grow as a player. But we can't discount that fact that he also played with Kevin Durant and we all know how it ended.