This section does not apply to a unit in the Department to the extent that the unit is authorized by law to employ its own legal adviser or counsel. The Attorney General is the legal adviser to the Department. The Attorney General shall assign to the Department the number of assistant Attorneys General that are authorized by law for the Department and its units. The Attorney General shall designate one of the assistant Attorneys General assigned to the Department as counsel to the Department and may not reassign that individual without consulting with the Secretary. The counsel may have no duty other than to give the legal aid, advice, and counsel required by the Secretary or any other official of the Department, to supervise the other assistant Attorneys General assigned to the Department, and to perform for the Department the duties that the Attorney General assigns. The counsel shall perform the duties specified in paragraph (2) of this subsection subject to the control and discretion of the Attorney General.