Now if we rerun Delete Duplicates (keeping Preview Only enabled) again but with Song is a duplicate if has same set to Same MusicBrainz song and same album (specific version) we get slightly more results.
We no longer need a matching acoustid, so here is an example where we two copies of the same song but from different sources so their Acoustid is different but they are matched to same album.
And so even though the songs have different acoustids they are both matched to the same track on the same MusicBrainz album so marked as duplicates
If we rerun again but with Song is a duplicate if has same set to Same MusicBrainz song and same album (any version) we get slightly more results.
Because the E:\Music\Pink Floyd\Obscured by Clouds (1) folder contains the complete album (10 songs) and the E:\Music\Pink Floyd\Obscured by Clouds folder contains only two songs the Most Songs in Same Folder criteria is used to decide the file to delete, and keeps the song in the folder with most songs.
Here we have duplicates songs matched to same MusicBrainz recording
but different versions of the Obscured By Clouds album