Tenn. Code § 58-1-201
The state headquarters of the national guard is hereby organized and divided into an army division and an air division, with an officer whose rank shall be designated by the governor as the head of each division; provided, that no such officer's rank shall be higher than major general. The head of the army division shall be designated as assistant adjutant general for army, and the head of the air division shall be designated as assistant adjutant general for air. The governor is further authorized to appoint for the army division or the air division a deputy assistant adjutant general; provided, that no such officer's rank shall be higher than brigadier general. Such officer shall serve at the pleasure of the governor and shall perform military duties as assigned by the adjutant general.
T.C.A. § 58-1-201