If they do have a physical advantage, it's the same as having longer legs or being taller. Some people are just naturally better athletes.
For the benefit of anyone who can't figure out the fallacy.
The advantage is not the same - the advantage is being male.
And we already have a place for male players. The problem is male players trying to get into the restricted classification for people without the male advantage.
If we did have separate classifications based on leg length or height, should we let tall people into the short people category? With the excuse "well, some tall people aren't better than short people"?
The male/female classification was created for a reason. That reason has not gone away. Letting transwomen play defeats the point.