I thought we all got enough of the Westbrook-less Thunder this year in the playoffs--you might not like his game, but Russell Westbrook is/was a force.
Rondo and Durant would be interesting for a couple of games, until the Thunder's opponents realized that Rondo's impact is highly mitigated when he's playing off the ball.
Rondo would still be playing his normal role on offense, I doubt he'd be playing off the ball much.
Right, but at a massively simplified level, any team playing OKC has one defensive objective--keep the ball out of Kevin Durant's hands.
Part of the reason Westbrook took so many shots in the last two seasons was because KD wasn't open, or because Durant was hanging out on the wings and the other team was patiently waiting for Durant to get the ball--in other words, trying to goad Westbrook into having to beat them.
You can live with Westbrook trying to beat you--he's not in Durant's class as a shooter (almost no one else is)--and he's similar in attack to Derrick Rose with more reliance on that amazing/infuriating split second pull up jumper. If that's the only guy you have to be worried about, than you're probably doing all right.
He's like a release valve for extra pressure on KD. If you take him out of the equation and put in someone like Rondo, who is excellent in an entirely different way, I'm not sure that Durant's game benefits as much as it does when he's playing alongside Westbrook, because the main goal is still going to be keeping the ball out of Durant's hands and Rondo isn't quite as scary as a one-on-one/make a basket after the play breaks down player as Westbrook is.
And, let's not forget, that Westbrook has been on pace to finish with points, assists, and rebounding numbers that we haven't seen since Oscar Robertson. And he's only 24. Its not like he's some scrub that's keeping Durant from getting all the points ever. They're a great yin and yang.