There are Series in MB that can provide a good basis for a compilation/Various Artists collection of tracks.  Consider the Rolling Stones 500 Greatest Songs series.  If a user has each file of this series they may not want to save them under their original albums (thereby creating ~500 incomplete albums with single tracks).

Rather it would be great for Picard to populate a Various Artists album with the track list from the Series.

Tagging-wise there would be no Release ID (as it does not exist as a release in MB).  I'm not sure if this would create problems.  There may be other tagging implications as well.

Perhaps this might be best done (if possible) as a plugin.