in 2009-10, he played in just 51 games and his averages dipped to just 6.5 points and 6.3 rebounds per game in only 22 minutes a night. So he wouldnt have been completely right for the 2009-10 50-win playoff run. He wouldve been able to contribute, no doubt, but not completely himself.
It's not like your team would have been winning the title that year

This begs the question the future of his contract
So we would be paying
westbrook 14-15
durant 16-17
and tyson what 12-13
So that means possibly no harden or ibaka for the future that's just stupid im sorry.
You run the risk of losing Harden or Ibaka as it is, and you could have traded Jeff Green for something else as well.
I don't see how you complain about Perkins all season long, and front like Tyson wouldn't be a big upgrade.