At present, every new Team creates a brand new Library which quickly means that document and user access control goes out of control.
In order to safely create a Team, it is necessary to:
- create the Team
- go to the associated Library and change permissions so that nobody can access it (this automatically means that any documents uploaded in Teams will be inaccessible, and it is impossible to remove the 'Files' link)
- create anew tab in Teams linking as a web page link to the appropriate Folder in the right Library, or using SharePoint if linking to an entire Library

We are a projects-based organisation running 100 projects a year and we need share comprehensive access to our project documents in a single library, not 100 new Libraries a year with legacy user access!