I hear what you are saying...But most of those names have really nothing to do with obvious Heavy Metal references that nearly the entire film was based on...
From "Smell the Glove" to spandex complete with a cucumber, to the Font of Spinal Tap, to the Stage shows of Stonehenge with druid motif and Rock and Roll Creation the cocoons and dry ice smoke...exploding drummers...That was ALL directed at Heavy Metal.
And I would say British Heavy Metal specifically.
I took a quick look at Wikiepedia - not the best source I know - and apparently Rob Reiner watched Judas Priest when he was putting the movie together. No question that Tap is a British metal band during the time of the movie (although they started as the Thamesmen in the 1960s and probably played something akin to early Pink Floyd to my ears). A bunch of the incidents are from other sources though. Tom Petty apparently had a video where he walked through a bunch of the doors to get to the stage and ended up on a tennis court. There was another group that had a succession of drummers. The band dates back to 1979 it seems and took a few years to develop the movie.