Wouldn't it then follow that all students of the same teachers end up with the same skill level in math? Not sure that's the case.

Cantor gave his life to the Continuum Hypothesis, Hilbert gave much of his life to similar goals.

You’re making an argument somewhat along those lines, but given that I didn’t stipulate a convergence condition your conclusions can be dismissed by me.

If it were a valid argument then we’d need Gödel.

Doesn't follow. Bell curve in, shifted bell curve out. Ideally this also tweaks the variance a bit.

In other words: Some students flourish despite their teachers, some flourish because of them.