The official website  of this release and all digital stores the release was distributed to , say “オレカ音楽隊” is the release artist. This is the digital version of something that was previously released as a CD with more specific artist creditation, so it is inferred that “オレカ音楽隊” is a pseudo-artist rather than a real artist.
@liftarn insists that “オレカ音楽隊” as a release artist is “incorrect” and should be changed to say “Various Artists”, despite the official website and distribution saying otherwise. Would you keep the intended release artist credit as provided?
I don’t read the language, so I’m a little hampered here, but I dealt with a similar question with the soundtrack to the movie “Grease.” The front cover credits John Travolta and Olivia Newton-John prominently, even though more than half the tracks are by other artists.
The soundtrack guideline says The Release Artist of a soundtrack should include the writers (composers and/or lyricists) and performers featured on the front cover. Use only writers and performers who are featured on the front cover (or the spine) ... If there aren't any clear featured artists (for example, for a compilation of film themes), use the special artist Various Artists. On that basis, the release artist for “Grease” is “John Travolta and Olivia Newton-John,” rather than VA.
I don’t see anything in the pseudo-release guideline to contradict that. So I would say, since an artist appears to be prominently mentioned on the cover of this soundtrack release, that should be the release artist.
The digital release is just a reissue of a previously released soundtrack, and I don’t see the group name having any meaning, since it doesn’t appear on the physical release artwork as I can see. It is seemingly only used to make the album be linked to an artist page on digital retailers. I would add this as various artists, but I wouldn’t change it if it was already added.
It would be nice to know how to handle cases like Young Stoner Life, which is a label/collective name, but the group name also appears as “[artist] & Young Stoner Life” on the lesser known members releases.
オレカ音楽隊 translates to Oreca Band, where Oreca is a shortened version of the game name in title.