I'm not sure what you want to refer to as genre, sub-genre, and what the purpose of tags will play in it. Let's just say that sub-genres are still considered genres, they're just a deeper dive. Are we now saying that a Romantic Comedy sub-genre has to be listed as both Comedy and Romance? Or Psychological Thriller or Crime Thriller has to be listed as both its individual genres?
Those questions being asked for consideration aside; even in Western television/movie listings, these are considered official "genres" not sub-genres and should be listed [some Western examples provided for clarity]:
*Manga adaptations with living people is consider a whole genre in itself: Live-Action Drama.
*A drama with a different story and a different set of characters in each episode: Anthology Series
*Extended dramas: Soap Operas
*A program depicting some sort of historical or current news event, with specific changes or fabrications for legal, continuity or entertainment reasons: Docudrama
*A drama about music is not the same as a singing drama: Musical
*The stories revolve around a crime that has been committed and must be solved by the end of the episode following a very generic and usually unchanging structure of events are not considered "legal" dramas, i.e. law & order, dragnet: Police Procedural Drama
*Type of drama series with a major focus on teenage characters, i.e Beverly Hills 90210, Dawson's Creek, Gossip Girl, etc.: Teen Drama
*Depicting a real contest, typically a trivia competition or physical challenge, with rewards in prizes or money: Game Show
*A genre that documents purportedly unscripted real-life situations, often starring unknown individuals rather than professional actors: Reality-TV
*Entertainment made up of a variety of acts including musical performances, sketch comedy, magic, acrobatics, juggling, and ventriloquism and is normally introduced by a "Master of Ceremonies" or host, i.e. Saturday Night Live, Running Man, Royal Variety Performance: Variety Show
After adding the above additional genres to the list of General Genres, I'd consider the list complete, and I am okay with moving the finer descriptions of a drama/movie to the tag location. Also, it would be nice to have the tags streamlined and cleaned of duplicate information. =)