When adding an artist with the same name as an existing artist, a second dialog is shown, asking for confirmation and a disambiguation comment.

However, with the AC-on-relationship changes, many "legal name" artists are being merged into their (primary) performance name entity.
Because searches for the "John Smith III" will not always make it clear that "Foo" is being returned because Foo's legal name is John Smith III, this could lead to attempts to (re)create a separate "John Smith III" entity.

As such, the "duplicate check" should probably be extended to include legal names and/or all primary aliases (that would also prevent adding "Pyotr Ilyich Tchaikowsky" instead of using the correct artist).