We are creating a website in drupal 7 for my church. The website is pretty much complete and about ready to go live. However we want to be able to create groups based on the various different areas of the website. For example we have a section for children and families so we want to create a group called children and families where members have the ability to edit and create children and families content but we don't want them to be able to create new users. We want each group to have a leader (administrator) who has overall responsibility for the group and a few authenticated website users (chosen by the group admin) who have permission to edit content.
We have investigated organic groups, but we don't want any old website user to be able to subscribe to the groups as this would give them the ability to edit content, we do however want all website users to be able to view content. Because of these requirements organic groups doesn't appear to be the way forward. Does anyone have any ideas on how we can achieve this?