Thank you for the post.
The following is from the FileMaker Pro 12 Help on “Editing existing accounts”:
“At least one active, FileMaker-authenticated account in each file must be assigned the Full Access privilege set. An error message will appear if you edit accounts so that no active account is assigned the Full Access privilege set.”
If an Active Directory group were allowed to be the only [FULL ACCESS] account and the database were removed from the FileMaker Server, then [FULL ACCESS] would be lost.
However, using FileMaker Pro Advanced “you can use the Developer Utilities to remove all administrative accounts from a file.”