Yeah, we can all get anal retentive about this. I thought you mostly covered it. When I categorize my music into folders I tend to put rock, classic rock, heavy metal, alternative, grunge, prog, new wave, punk, and so on into the same folder. For my tastes, Pop, Blues, Instrumental Rock/Fusion, Reggae, Indie, Acoustic, and Rockabilly get separate folders. IMO, these don't blend as well with the first group I listed. Though some blues-rock does surely cross over. It's not perfect. All these folders are in a "Rock" folder.
I have a "Jazz" folder that has in it a range of categories based on what I like to listen to for a certain mood also.
I only picked two categories because they're my go to when I listen to my own stuff or while streaming.