In G6 RW had TWO major flops (in whole game) and THREE turnovers in last two minutes of the game.
Also KD had TWO turnovers in last two minutes.
Yes, GS is a two man's team but unlike OKC they are involving their teammates with purpose, unlike RW and KD who are doing that only by accident - mostly by missing shots.
GS is playing more team basketball and thats why they should advance. And because they can beat CLE (OKC can't beat them).