KD is an incredible player. Steph, and the team, change their natural game to take advantage of KD's strengths.
I'm not sure we can say how the team, and/or Steph, would have performed against Houston had KD not been playing.
All of the statistics throughout the time that KD has been with the team show that the Warriors (and I will assume Steph) perform, statistically speaking, at a higher level without KD.
I think it's difficult to make these definitive statements. They are both great. They both have a different game.
KD could not win in OKC. The Warriors won without KD. The Warrios won with KD. It's a team game. The team has been great with and without KD.