Sometimes an album is re-released years later by different artists and the very same (or mostly the same) songs. For instance:
• Release “A arca de Noé” by Vinicius de Moraes - MusicBrainz
• Release “A arca de Noé” by Vinicius de Moraes - MusicBrainz
It seems lookup only looks at titles, artists and durations, and ends up putting all eggs in the same basket. If it looked at release date (year, preferably), I suspect it wouldn’t incur in that mistake.