That is massive headroom overkill happening there Dave.
35 years ago I used 100W Marshall Super Bass Head with 4 x 12" 25W greenback Celestions Quad Box as it was originally from I was playing guitar. Was so loud it never got anywhere near speaker distortion levels. Mostly played 'just on' somewhere near 1 and on odd occasions bumped up to 2 which had my ears ringing for the next couple of days. Due to inept PA's of that era everything was super loud.