How well organized is your collection currently ?

Your collection may already all be well organized into artist/album folders representing each album, with perhaps sub folders for multi-disc albums, and each folder containing a full album. In this scenario you probably want to enable Only allow match if all tracks in albums were matched, but if some of your albums are not complete you would not want to.

Consider what was the original media format (CD, Vinyl, Digital) and country of release of the majority of your collection and set these options accordingly in Match options to ensure you get the optimum match.

If your folder contain a group of random songs that do not belong to a single album then SongKong with the default options SongKong will be able to match the songs to MusicBrainz songs but not MusicBrainz or Discogs albums. You may only be concerned with songs and not releases but if you disable Only allow match if all songs in grouping match one album SongKong may be able to group some songs to releases, however disabling this option and renaming files can break up folders if you have Rename files based on metadata when matched enabled

If you have a mixture of folders some already well organized and some not one approach is to work on certain folders first, and then change the options before processing others folders. Another approach is to run SongKong with the most stringent matching criteria first and a Move matched folder enabled so that all the folders that match that stringent criteria are moved out of the way. Then you can rematch the remaining folders using less stringent criteria.