FWIW I really don't think the Perk trade was for Jeff Green, it was for the Clippers' pick. Jeff Green just made the deal look superficially more justifiable since he added bench depth. Perk was pretty turrible for the Thunder last year so it wasn't a huge loss, would be nice to have him around this year but doesn't seem like Ainge was down to pay him.
Of course Green's heart ailment and CP3 going to the Clippers makes the trade look not nearly as good, but that's results oriented. If nothing else Krstic was just as good for us as Perk was for the Thunder, so people are way overreactive to the loss of Perk for last year at least.