Obviously this won’t work for all sports, but things like football, track, soccer, it would allow for de-gendered team, even allowing athletes with the skills but not the genetically-endowed physical attributes to have a place to play.
Note: I know very little about sports and being on a sports team, so please point out anything that doesn’t make sense.
Castrato is just Italian for castrated or neutered, even used with animals albeit mostly used referring to males. Sometimes it’s even used figuratively. It would still work perfectly with your example, I think