The Adjutant General will be assisted by an Assistant Adjutant General of the Army National Guard in the Department of Military Affairs and an Assistant Adjutant General of the Air National Guard in the Department of Military Affairs. They shall hold the rank of Brigadier General. Such individuals shall be appointed from the active or retired list of the Army National Guard and Air National Guard respectively by the Adjutant General and shall have served as commissioned officers of the Delaware National Guard or armed forces of the United States and shall serve at the pleasure of the Adjutant General.