Except as otherwise provided in this section, the commanding officer of a garrison, fort, post, camp, air base, auxiliary air base, or other place where troops are on duty, or of a division, brigade, regiment, wing, group, detached battalion, separate squadron, or other detached command, may convene a special court-martial. A special court-martial may also be convened by superior competent authority. If the commanding officer is an accuser, the court shall be convened by superior competent authority. A commanding officer shall not convene a special court-martial without the written consent of the adjutant general.