Wall, beal and Durant would mesh together better than Westbrook, Harden, and Durant.
Wall is more a pass first point guard who gets everyone involved, whereas Westbrook is more of a playmaker, and a score first PG.
Beal is a pure shooter and runs the court to get open to shoot, whereas Harden is more of a playmaker and needs the ball in his hands to operate (similar to westbrook).
The thunder's 3 were 3 playmakers who need the ball in their hands to dominate. With the wizards, you have a distributor, a shooter, and then durant whos the playmakers.