Main Albums vs Appearances logic for different but related artists?

So I am curious about the logic behind why albums are listed under multiple artists. Let me explain…I have two different yet related artists, Neko Case with albums A, B, C and Neko Case & her Boyfriends with albums D, E. When I look under Neko Case, albums A, B, C, D, E are all listed as Main Albums. When I look under Neko Case & her Boyfriends only albums D, E are listed. My questions are:

Shouldnt albums D, E be listed under Appearances instead of Main Albums for Neko Case?
Why dont albums A, B, C appear under Neko Case & her Boyfriends (under Appearances)?

Neko Case:

Neko Case & her Boyfriends