What is the gap for a character to no longer be capable of damaging the other person?
And can we say that those with high-levels of tenacity/pain tolerance/will power can continue fighting even after being hit with an attack above the one-shot value, assuming it isn't enough to break every bone in their body or something?
And on that note, wouldn't it be more useful to give a list of gaps, and what they would entail? I think that would be a lot more useful.
For example, you could have:
5x Gap: The gap between a normal human's punch and peak human's punch. Well-placed attacks could instantly knock-out the opponent.
14x Gap: The gap between a normal human's punch and the energy required to shatter a human skull.
??? Gap: The gap between a normal human's punch and the energy required to turn a human into paste.
Don't pay much mind to the specifics or the descriptions, those can be changed. It's the concept that matters. The idea of having these multiple gaps that give insight as to how much they matter in a matchup.
Things like that. For VS matches, it would be infinitely easier to quantify how much of a gap a character would be able to withstand, given their tenacity, regeneration, immortality, and other abilities.
Having one standard value just makes things difficult.