Every player and pieces matters, but you cannot credit Barnes (and thus, their tanking) much for their 2015 chip or 2016 finals. It was Steph, Klay and Draymond who led them, and Barnes was in the 2nd tier with Bogut and Iguodala (arguably worst of the 3). Barnes was a starter for sure, but its not like he provided consistency or skillset they couldn't get from someone else (bench or lower pick) that year. After KD signed, Barnes impact was erased and he would have been glued to the bench anyways.