You asked ...… "if Mahomes had Jason Garrett as head coach as opposed to Andy Reid you think his numbers would be the same?" as if you're somehow expecting people to think that If Mahomes and Dak or Romo switched places then there would be no difference in the teams. It's all about Reid vs Garrett. No, It wouldn't matter because true greatest would still shine through. Mahomes is all time great already. Romo is not, and Dak so far is not.
What's that got to do with Mahomes play in the Super Bowl? You're picking out one game, which happens to be THE SUPER BOWL, to try build whatever your argument is on.