Right, but that would be an argument that NL pitchers have better numbers. Maybe that's true, maybe it isn't.
However, even if we stipulate that it IS true, it doesn't make AL pitchers BETTER than NL pitchers. Having worse numbers doesn't mean you are a superior pitcher.
No, but I think it means you can discount stats as apples to apples. You can excuse away why AL numbers or worse or could say that if the numbers were the same, that NL numbers being even despite an advantage is a sign of inferiority.
I'm not saying any of that is actually true, just that it is a logical argument to make.