My approach to Nyotalia, because I really dislike it when the characters are seen as just cisbends of the original countries, is to treat it as SATW (a comic similar in theory to Hetalia) treats it. Which is that they all exist and interact with one another as separate characters– representing the same country.
I’ve seen other people treat Nyotalia this way, and in my opinion it’s the best way to go about doing it. Nyo! America and America aren’t the same person– they’re not “bent” genders of each other. They’re their own representations of America.
I can’t speak for Hima, of course, and I don’t know his original intent with Nyotalia, but as a trans person, I don’t like thinking about them as “genderbents” of the guys.