Biography
This tag is not 'incorrect' (in fact, this is the order of the two names on the sleeves of both the 'Superwolf' and 'Superwolves' albums, so it's totally good), but please note that the most popular and common tag for this collaboration here on Last.fm is Bonnie 'Prince' Billy & Matt Sweeney.
Biography text from Last.fm, available under CC BY-SA.