I think people here are confusing what Menzter advised in training when he retired with how he actually trained in his competitive days. I have no problem believing his gains came from his variation of HIT and not traditional volume, because his actual training was pretty good actually..2 day split, training 4 days a week, body parts hit 2x week, more volume than just one set per bp, etc.
Now, what he recommended in his latter days, the whole one set per body part once every full moon and the such was just bullshit.