“I could point out that trans-Napoleonism seem to be mysteriously less common than transgender”—well, because the Napoleon is a far more specific thing than (wo)man, nothing mysterious about that (even ignoring the fact that you are squaring off one (trans-Napoleon) against two (MtF and FtM). A better example would perhaps be something like “Asian feeling themselves as Caucasian” or - a broad category of a really small set (even if there are more than two genders I doubt many people would claim there are more than ten).
“I could point out that trans-Napoleonism seem to be mysteriously less common than transgender”—well, because the Napoleon is a far more specific thing than (wo)man, nothing mysterious about that (even ignoring the fact that you are squaring off one (trans-Napoleon) against two (MtF and FtM). A better example would perhaps be something like “Asian feeling themselves as Caucasian” or - a broad category of a really small set (even if there are more than two genders I doubt many people would claim there are more than ten).