What’s interesting is these guys’ insistence on drawing a line they don’t seem to be able to draw without even questioning their own original division by sex of sports (whatever that means!) Maybe, just maybe there is NO clear-cut line to be drawn where they insist on doing so! This is where we cannot even define what is “fair” in sports (like you mentioned the height, for instance).
On the other hand, sports are social concepts. We have created them and, the ultimate fairness aside, we can still measure skills and performances and draw as many clear lines as possible there. Why don’t we define leagues or tiers and for each, set performance/skills tests and guidelines and let “athletes” simply strut their stuff and play in those leagues? This is something they do in para-sports, as one example, not to mention the weight categories in some sports, as another example. Plus, everyone is already used to the idea of A-league, B-league etc.