Where are the source files from? If you have ripped your own CDs, then Picard is easier to work with. Easier to check
If this is a heap of tracks from various random torrents, then you will need to to a fair bit of double checking. Yes, Picard’s Scan is excellent - but not perfection. Maybe 95% hit rate. So 1 in 20 may be out. The rougher your tags, the lower quality the audio, the more misses you’ll get.
Go into OPTIONS \ METADATA \ PREFERRED RELEASES and mess with the sliders. If you have a heap of files and just want names an images, then you are less interested in Compilations. So push Compilations to the left, and push Album\Single\EP to the right.
AcoustIDs will be matching tracks on all kinds of sources, and this includes compilations. Kick these sliders around to twist the priorities of the match. Otherwise you may keep getting artwork from NOW collections.
If you have good CD rips, then you’ll get whole album matches. “Lookup” will work better for you if you have good tags.
If you have junk tags and just want to ID things, then SCAN will “listen” to the track and make a “best guess” match.
Also in Picard, go look at the OPTIONS \ PLUGINS and find “The AudioDB cover art” and “Fanart.tv cover art” to get a wider selection of artwork if image is more important than accuracy.
So what do you have? And what is your aim? the point is Picard is a main bladed Swiss Army knife that has the tool for what you need, if you sped time working out how to tune it.