In my opinion, wanting the benefits of the patriarchy is different than wanting to be a man, with the acknowledgement that there can be some overlap between the two. Where Mulan’s military service was temporary and brought about by external pressures, a trans man likely would not need the threat of an elderly family member being drafted to war to make the change, nor want to go back to living as a woman. But at the same time I’m sure there are women like Mulan.