Situation:
Album originally released under one name, later re-released under a variant name.

Intention:
Add re-release, credited to new name variant

Procedure:
Go to release group page, choose "add release".
Enter release artist credit.
Use tracklist from existing release.

Note that all tracks are credited to the "main" artist name.

Solution:
Make "Change track artists" in the release editor into "Set track artists" for the add-release editor. Show it on the first page.