Here's the problem, Fox will likely beat some midtier fighters and many lower tier based on his/her/xe/it's physical abilities alone.
If I recall correctly, Fox fought a female fighter, and the fighter it beat said Fox's strength is unnatural and different than a woman's
Of course this could be a lesser fighter's way of coping with defeat while saving face (similar to claims of pre-existing shoulder injuries, wrong socks, etc.,) but you have to take into consideration that Fox's physical advantage put xe at a different class based on that alone.
On a similar note, wasn't there some discussion about how trans people competing in the Olympics? If they can't then why would Fox be able to.
Same logic applies if trans are allowed to complete

What a time to be alive in America