Right, but that isn't the case with Pai Mei... All we've seen him fight were trained deadly fighters. All the monks he killed were clearly versed in Kung Fu. As mentioned previously, he casually and jokingly dealt with The Bride, who herself displayed superhuman feats. Everybody we've seen him deal with wasn't just your average human. They were trained fighters, deadly fighters, and he casually beat them.
I know what Pai Mei did. And yes, while the people he fought were skilled. None of them were superhumans who could move faster than the eye could see, chuck ninja stars like high powered automatic rifle bullets and casually chop people into ribbons.
You keep trying to equate skill in Kill Bill to skill in Ninja Assassin and Ninja Assassin is simply on another tier of power. And being the most powerful guy in Kill Bill doesn't make Pai Mei the most powerful guy in NA, not by a longshot.
It's like saying Inigo Montoya could beat John Preston in a sword fight. Inigo is one of the best in his world. But his world is far below Equilibrium.
As we can see here... The Bride was doing superhuman moves herself i.e. just as your claiming for the Ninjas. She's shown easily cutting off limbs as if it was nothing.
https://www.youtube.com/watch?v=a3aFv8IQb4s
Guess what, Pai was CASUALLY and jokingly dealing with her. I mean it was so casual it was almost a joke. Raizo wasn't casually dealing with the superhumans he fought. In fact, it was quite the opposite. It's odd to me that you're getting how easily Pai Mei dealt with The Bride, to be honest, really puts him on another level imo