Yes.I might look into something like that.
Also, and bear with me for a moment, as a completely random side, is "Manwha" really a genre? Manwha is what the Koreans call their "graphic" novels (comic books). That would be the same as saying that the entirety of "graphic novels" (comic books) are a genre in and of itself, as "graphic novels" (comic books) are what English speaking countries call the... well... classification of media.
Don't get me wrong, you could be (and probably are) completely correct... I just thought of "graphic novels" as the same categorical concept as "novel" (book), video/movie, audio (book), stage play, etc. And saying it is a genre (again, I could easily be wrong, and that it is one) would mean that people from other countries would be able to (independently) produce works of the same "genre." i.e. A Chinese individual would be able to make a Manga, instead of a Manhua; a Japanese individual would be able to create a Manhwa, instead of a manga... etc (I could try and find the word for "Graphic Novel" in each respective language, but that would take too long, too much room, and do nothing to further my point). I'm fairly sure that people from [X] country would object if people from [A - W, Y, or Z] country claimed to make something classified as "work from [X] country." I think there was actually a lawsuit by Native Americans (either a specific tribe, or a class action one) against a (or group of) clearly non-Native American(s) for creating works similar to and claiming that it authentically was Native American work.
But... The entire premise of my question rests on whether or not a "novel", a "novella", a "textbook", and other categorical form of media are themselves considered "genres" and not just categories.
Long strip is the format, but manwha means "long strip format with chinese/korean (because I can't bother to differentiate the spelling today, even if I usually do) influences". Same reason "manga" and "western comics" can be considered genres.
Yes, there's little stating that they have to be written in a specific way. But they almost always are.
But indeed, if we are speaking more clinically, no they are not. They only refer to format, art-style, and 'country' of origin. It's just that those combines to have a strong bias. But exceptions exist, and ie. "avatar the last airbender" is a cartoon, but if the terms were considered genres it would have to be called an anime instead.