Summary courts-martial must be appointed by the adjutant general and by such other commanding officers of the National Guard as may be delegated such power of appointment by the adjutant general. The power to appoint summary courts-martial, when delegated by the adjutant general, may be redelegated repeatedly from higher echelon of command to lower echelon of command as is considered best by each successive commander delegated that authority. Summary court officers have power and authority to administer oaths.