A woman is a person who identifies as a woman.
I'm going to repeat what's already been said at least once on this thread. That doesn't work.
To identify as something is a signaller that it is something the person isn't already, and to identify as a woman logically has to mean that there is a fixed meaning of what a woman is: a biological female. This is language to express someone identifying as something specific that they are not. Which is fine as a concept btw.
That definition logically means 'women is adult human females and adult human males who identify as women'. That is not one classification, you haven't achieved the grounds or terms that make them into one classification.
And it's by the by, because the issue still is, however kind you want to be and nice about language, and however lucky you are in your privilege that you are able to share mixed sex spaces, many females are not.
The 'enemy' as you put it, is female people being left without any provision at all.
That is the very real, immediate, already happening issue for females as a class. Is that a problem to you? Or is your concern and kindness prioritised on male people who identify as women? Who incidentally already have provision now, and could have any sort of additional provisions to meet their needs, but want to totally remove and have female provisions. Which will exclude some females from any provision at all.
Is this something you're ok with?