Sally, a number of the Photo Officers I served under were what the Navy calls "Mustangs"; former enlisted men who by dint of opportunity and ambition, were able to achieve commissioned rank. Mostly, these officers stayed within their specialty, but not always.

Bryan is correct in his explanation of the differences in American and other countries' military. Part of our training for combat was in knowing as many jobs of those around you as possible, and where you stood in the chain of command. When necessary, the next senior man (or woman) takes charge of the unit.

In combat operational planning, the entire unit, down to the last private, seaman, or airman, is told what the plan is, so the mission can be accomplished no matter what. Part of the success of D-Day was this thorough training. When units, particularly paratroopers, were dropped in the wrong landing zones, or were separated by wind and wayward planes, they simply formed into ever expanding groups as they found each other, and did the job, while at least two Panzer tank divisions could not move to counterattack because nobody would awaken Hitler to give permission.

Both sides in the WBTS learned innovation, or they got beat. Stan