well, it's not strictly a matter of looking at WAR. you also have to consider roster depth and who you are replacing. Mind you, I would not part with Ross, but the argument is that if you have someone in the wings like Giolito or Fedde or Taylor what's his name, you look at the drop off there from ross and look at the pick up in bullpen chain, as well as where you are on the contention curve, to decide whether the move makes sense. I don't think you build a team for the long run by ignoring WAR, but you may be at point where moving a specific player makes contextual sense.