The Secretary concerned may direct the Judge Advocate General to establish a branch office with any command. The branch office shall be under an Assistant Judge Advocate General who, with the consent of the Judge Advocate General, may establish a Court of Criminal Appeals with one or more panels. That Assistant Judge Advocate General and any Court of Criminal Appeals established by him may perform for that command under the general supervision of the Judge Advocate General, the respective duties which the Judge Advocate General and a Court of Criminal Appeals established by the Judge Advocate General would otherwise be required to perform as to all cases involving sentences not requiring approval by the President.