> Linux still doesn't have anywhere near as nice and cohesive as Group Policy, Active Directory etc.

I take your word for it (I know of Kerberos and LDAP and Netscape and Sun trying to make such palatable, but clearly haven't followed that in the last quarter-century).

That assumes however the server to be currently MS Windows. For government agencies, I'd rather expect some Mainframe to be (and remain) in place. Surely IBM (or here rather Groupe Bull) has user authentication/authorization figured out (more than half a century ago, methinks).