Isn't the reason that women perform better than men at ultra long-distance swimming that they're more buoyant and it's such a long-distance / low metabolic rate

Isn't the reason that women perform better than men at ultra long-distance swimming that they're more buoyant and it's such a long-distance / low metabolic rate pursuit that structural efficiency (more buoyant body) is the dominant factor of performance? I swam in college competitively through the NCAA level and this was the accepted wisdom amongst my peer cohort. If this is the case, respectfully, I don't see it in conflict with the thesis presented by the two articles cited in the OP Twitter thread that got banned (i.e., that people who went through puberty as males have a categorical advantage in athletic pursuits over those who went through puberty as females). If it is not, I'd be interested to learn what's actually going on! A very interesting outlier to be sure.