I was about to put in a new release and got confused by the album artist, or lack thereof.
On this album, there are no artists credited on the cover or back. But in the inside of the booklet, they list all the performers (9 of them - with their instruments).
The tracks don’t indicate different performers (although half are instrumental only), so I would assume they could all be credited for all the tracks.
In this case you might just want to put them all in. If there is no unit or track specificity, just do Artist1, Artist2, … & Artist9 as the release, album & track artist.