The person acting on behalf of the accused is known as "The accused's friend" and even in my day that, nine times out of ten, was the accused's Divisional Officer or one of his friends who was prepared to act on his behalf (No legal training required), if you had the sense to do so you, as accused, could personally elect to engage the services of a civilian barrister who was familiar with military law ( A good QC normally would run circles round the duty naval prosecutor), there are law firms who specialise in this area.

You may remember Terrikins that the leaders were not allowed a defence.