But purely sound-wise, did any of those 3 bands kick the door of hair metal off it's hinges and send it hurtling to it's death, like Nevermind did? I'm asking because I don't know how those bands sound. Were they really as earth shattering as Smells Like Teen Spirit?
No.
In 1991 Guided By Voices were unknowns outside of Ohio. And Pavement weren't really a band yet. Sonic Youth were an underground mainstay, but they couldn't write a song to save their lives.
None of them could have done what Nirvana did. Even with subsequent work.