This is what the Soundtrack style currently says for track artists:

If the cover art lists specific artists for each track, that artist should be placed in the track's Artist Credit field. If there are no track artists, use the release artist instead. If there is no release artist, use the composer for each track instead. If the composer is unknown, use [unknown].

I think it should be changed to

If the release lists specific artists for each track, that artist should be placed in the track's Artist Credit field. If there are no track artists, use the release artist instead. If there is no release artist, use the composer for each track instead. If the composer is unknown, use [unknown].

Because on many occasions, the track artists are mentioned in the booklet or some other way.