So the album/EP in question is Supreme Team's Spin Off. MB already has the six track digital EP version included, but there is another version of the release that is an album, and it's a repackage album of Supremier, meaning that its tracklist shares more than half of its tracks with Supremier and half of the new tracks are simply dirty versions or remixes of tracks already on Supremier.
As it is, I can see three ways to approach this release:
1) Leave both Supremier and Spin Off EP as their own release groups and create a new release group for the Spin Off album.
2) Leave Spin Off EP alone and add Spin Off repackage album under Supremier's release group, since it's largely a rerelease of the same album.
3) Leave Supremier alone and combine the EP version of Spin Off into the album's independent release group--although since it contains both an EP and an album, I'm not sure how to categorize it.
I'm leaning strongly towards (1), because it seems the clearest approach, but I wanted to get some input before I got going on adding the album. Let me know what you think. Thanks!