This thread is dancing around the fact that Sri Lanka's bowling didnt have the depth to trouble India in the same way that Paksitan or even Australia and SA did.
Malinga had a dream first spell - but nobody else - including Murali or Malinga's subsequent spells - were able to create sustained pressure from that excellent start. Mendis would have to be formidably a better spinner than Murali or Randiv, and Matthews significantly more attacking a bowler than Kulasekara or Perera to make a difference.
In fact, having to replace Mathews with 2 seamers who could bat probably didn't hurt. Had SL really played 3 spinners, and elected to bat - wouldn't the dew factor hamper the 3rd spinner at least as much as the 2 best spinners in their squad?