This is by far the most compelling argument for the reality of Transgender identity. It is pretty much what Buck Angel believes about his own gender identity. It also contradicts the widely shouted slogan that anyone can be whatever gender they say they are. If we accept what you are saying here, then if someone says they are transgender and they do not have the differences in brain structure you describe here, then they are mistaken.
I'm willing to believe pretty much anything that the Medical and/or transgender community say on this topic. But I can't believe something that is self-contradictory