I always use to add the individual members as composers/lyricists to a work using release credits / ISWC.net or other sources (interview, biographies,…) rather than the whole group.
Example: In early days the album Trespass by Genesis is credited “all songs written and performed by Genesis”. Nevertheless I would credit each song to the individual members of that time (Banks/Gabriel/Phillips/Rutherford/[Mayhew]) and even drummer John Mayhew was removed as writer, because later it become apparent that he did not contribute to any of the songs.
So I started a discussion on the recent edits for the work https://musicbrainz.org/work/9d36c06b-f07c-4e26-a8ed-e9d860dfda20.
I would prefer the song being credited with the individual persons not the whole group:
I found no specific style guide.
Any hints, opinions?