If a team like the Thunder lets the big three try and outscore them we are toast. TD can't score 1on1 against Perk and Ibaka shuts down the lane for TP/Manu. We could only manage 90pts against a porous Mavs D, and if we get into a halfcourt battle with OKC there will be times when we just can't stop KD/Brook.
This is why I think playing halfcourt ball with two-big lineups plays right into OKC's hands. Perk and Ibaka will stop any team's offense more than their defense will stop KD and Westbrook. That is essentially Brooks' equation, and it was fully on display for the first half of game 1 against Memphis. If they play at that level and we play their game, we just can't beat them.
I don't think it's a coincidence that the team that matches up best with the Thunder (Heat) plays a ton of small ball. If you're going to score consistently enough to beat them you have to make them put Durant at the 4 and choose between Perkins' post D or Ibaka's rim protection and offense. If both are on the floor and they are playing up to their capacity as a defensive unit you just won't outscore them.