Music videos
Have you considered including those as local extras to your music library?
https://support.plex.tv/articles/205568377-adding-local-artist-and-music-videos/
Videos will show as concert / music video / live video / … on the artist page.
If that’s not working for you, your best shots are going with an other-video type library or looking for some 3rd party agent that deals with music videos (not aware of one).
Individual cartoons
Would you mind sharing some details on those?
I’m often surprised of what kind of stuff is going as a tv-show 
