Soundtracks aren’t fundamentally different to singles/albums of songs.
These 3 release groups need to be kept separate per any reasonable interpretation of multiple Style guidelines:
https://beta.musicbrainz.org/release-group/db46063c-6347-4097-bd77-828fc378b5af
https://beta.musicbrainz.org/release-group/1f41a12a-e120-4feb-b8bf-d953cc72f670
https://beta.musicbrainz.org/release-group/a7baa8db-4169-4c08-baad-67116bd2bf68
If you apply the logic as to why those 3 release groups are separated to other cases that aren’t so obviously separate volumes / 2-in-1 releases, a reasonable person should still be able to conclude that if they have a 10-track release, it’s not a different edition of a 60-track release (ignoring bonus tracks / bonus video discs.)