(1) A Summary Security Guard Court may be held by the Commander of any unit of the Security Guard and he alone shall constitute the Court.
     (2) The proceedings shall be attended throughout by two other persons who shall be officers or Assistant Commanders or one of either, and who shall not as such, be sworn or affirmed:
     Provided that the persons attending the Court for the trial of an officer shall not be of a rank lower than the rank of that officer unless in the opinion of the convening officer recorded in the convening order, officers of such rank are not, having due regard to the exigencies of public service, available.