Read the two fields separately
Kodi documents album-artist metadata separately from track-artist information. If a compilation or guest appearance produces unexpected artist groupings, inspect both fields before replacing every performer name with a single value.
Use one credited exception
Choose a track with a guest performer and compare it with an ordinary track from the same authorised album. Write the intended track credit and shared album identity in a small inventory. Preserve the original tags before any correction.
A useful result retains meaningful performer information while giving the album a consistent identity where appropriate. It does not rewrite a genuine multi-artist work merely to reduce the number of names visible in the library.
Review the scan before adding online data
After the relevant tag change and scan, inspect the resulting album and artist entries. Hold supplementary scraping until the identity is understood. If two input layers change together, a later mismatch becomes harder to trace to either the source tags or the online match.
Questions answered
Must every track artist equal the album artist?
No. They describe different relationships and can legitimately differ.
Can an album-folder rename replace this tag review?
No. Inspect the actual embedded fields used by Kodi's music scan.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.