You surely must have a consistent system for administrating these boxes with hundreds of them, no? If you could access all those boxes without any credentials whatsoever, couldn't anyone else?

Do you have an account that can list "dollar sign" shares on the Windows servers? That might be an option. For Linux though, there isn't much you can do unless you export the whole filesystem in NFS with no auth necessary, but that's a really bad idea.

Whenever you connect to another server, you pretty much need to have an account (login) to do anything.