I just put physique in to emphasize they are used for a boost in many ways, but confidence and adranaline absolute boost you're ability to take more punches than you normally would, even if it's 102 instead of 100, or whatever. At this level, marginal gains is what they are used for anyway. But again, I'm not even suggesting it really... they just seemed a bit powderpuff flurries, which even then, clearly had an effect at times.
And the guy who's not seen someone walk into them before.... he definitely has, just being selective. Sugar Ray beat Hagler with relentless powderpuff combos that effected Hagler less than today. (And yes, I know, he may have backed up... briefly, but didn't looked rocked once which Marshall did)