If you want to collaborate on one article d-tag, just have the client take the fork with the newest created_at, from within some community/relay or set a list of collaborators. Everyone has their own version, and you think up a scheme for which version is primary. Or you can have collaborators recommend their favorites. Which ever receives the most defers is listed first.
What you're describing is more wiki than longform article. You can include wikis in an index, like I did for https://next-alexandria.gitcitadel.eu/publication?d=gitcitadel-project-documentation-by-stella-v-1 (those are all 300818 wiki pages with Asciidoc markup, not 30041 articles).
https://github.com/nostr-protocol/nips/blob/master/54.md
