The JThink Music Server is a dedicated server that contains MusicBrainz and Discogs data, and is what Jaikoz and SongKong use for their automatic matching. Albunack is the public face of the music server and can be used to browse combined MusicBrainz/Discogs discographies for almost any artist.
If SongKong is not finding a match when you think it should, it is probably easier to check on Albunack instead of MusicBrainz or Discogs. Although note Albunack doesn't currently show collaborations or Various Artist releases (although they are in the JThink Music Server).
Two months ago we released Albunack and now we have now added a Youtube channel , and this includes an introduction to Albunack
this gives a nice overview on how to navigate around an Albunack discography.