I think this would be a valid argument if it weren't for the fact that even mid-teen male athletes are just way better than world-class female athletes. As far as world record 100m sprints go, which I would argue if one of the most impressive feats of strength, the world record youth time is 10.15 (16 year boy) while the current world record for women is 10.49 (which, by the way, in itself is way faster than the 2nd fastest). If the 16 year-old boy transitioned, are you saying he would not completely dominate the sport, easily breaking the world record? Looking at a more technical sport like soccer, it's not even close. In my country, which is one of the best internationally when it comes to women, the boys-16 team of one of the top teams played the women's national team. In my experience this almost never happens in top-level football so it's an interesting example to look at. The result? 3-0, and the boys played with one less player in the second half in an effort to even out the odds.