From the genderswap wiki: "A "genderswap" refers to the almost magical version of a sex change, wherein a character of one gender turns into one of the other sex without any medical involvement.
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If a character is genderswapped often enough, the genderswapped version may be given its own name..."
Naruko and Ranma-chan use the genderswap and genderswap_(mtf) tags, and the base character tags.
Kyonko and Suzumiya_Haruhiko use the corresponding genderswap tags, but do not use the base character tags.
It seems clear we should remove the base character tags from Naruko and Ranma-chan. It also seems clear we should either keep using the genderswap tags on all of them including Bowsette, or rewrite the genderswap wiki.
In any case, we should make a note somewhere (presumably in the genderswap wiki) that if a genderswapped version has its own name, the base character tag is unnecessary unless the base character is also present in the image.