I had someone actually try to argue that the constitution didn't SPECIFY the AG as a principal officer of the USA, therefore Congress could revoke that status. And, yes, skip the advise and consent stuff, the AG then being an inferior officer (see my excerpt from Article 2...)
He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments.
Nope, don't think there's any way to construe the AG as an inferior officer. (not that Whittaker wouldn't be grossly inferior, Heh)