The turnover argument is silly, LeBron's TO% is actually higher than Russ', the higher turnovers are just a result of increased usage. Russ has a BPM of 14.8, LeBron has 8.2. The Thunder's team rating goes down by over 10 points when Westbrook is off the floor, the Cavs only dip by ~6 points.
The Thunder are on pace for 47 wins in the West. Given that the West is a more difficult conference, I don't think it's crazy to assume that they'd win 3 more games by being in the East making them a 50 win team and right there for the 3rd seed in the East. The 50 win argument is pointless anyway, by this logic someone could average an efficient 50, 20, and 20, but because his team won 49 games and there isn't much of a precedent for it he can't win the MVP. In case you didn't realize, Russell Westbrook is averaging a triple double, the seemingly unbreakable record along with Wilt's 100. A 30ppg triple double. All 'precedent' should be thrown out the window. Furthermore, he's had to play through injuries to an already lacking cast of teammates. Oladipo and Kanter missed a significant portion of games, it's safe to say they'd have won 50, just 3 more than they're currently on pace for, if they were just healthy.
If you give them +3 for health and +3 for switching to the East, they're a 53 win team. Guess who else is on pace for 53 wins? LeBron's Cavs with Kyrie Irving, Kevin Love, Tristan Thompson, etc.
Russ hasn't missed a game this year, LeBron and co. are taking days off.