Assigning edit permission to specific articles (not just namespaces)

I want to have a Shared namespace where different groups can only edit specific articles - not the complete namespace.

Is there a way to do that? i thought of activating Approval and doing the permission check via a workfow but that would be quite a task for that.

Special:Protected Pages also sadly only allows Admins and not specific other groups.

Page Assignments as far as i know also doesnt influence that?

i guess not then? would have been a very useful feature