When I was a young rockape the Commandant General of the RAF Regiment was a two star pilot, and the most senior rock was a one star. Subsequent commandants general included some regiment officers who had made it to two star, with a further sprinking of pilots. Nowadays I believe the post has been reduced to a one star job.
Similarly an old pilot mate of mine finished his career as Provost Marshal, as good an example of poacher turned gamekeeper that I ever knew!
Plenty of precedents for non-specialists being put in charge.