While I'm not at all averse to the idea that there may be "subcategories" of each biological sex as well as know that there are people who are intersex, generally speaking, it's a no-brainer to divide competition teams into male or female.
I know a few transgender men (ie born female) who I fully believe are trapped in the wrong bodies due to errors in the womb. If the "wrong hormone flood" happens when the brain is being formed after the "right hormone flood" happens while the genitals are being formed, then the biological sex won't match the brain's gender recognition. It happens.
Personally, I've found trans-men to be so much more reasonable than trans-women. Trans-women seem to be so difficult and demanding IMHO while trans-men just want to live their lives as the gender they identify with. Of course, my personal experience is limited to only 4 individuals, 3 trans-men and 1 trans-woman so I can't say with any authority that those attitudes are true for a majority, but they are true with them.
Anyway, my point is that it doesn't matter if there are relatively minor variations in biological sex that divide both sexes. Overall, the two major variations are what matters in SPORTS.