In Hong Kong circa 1967/8 was an Army officer called Major Eric Sergeant. His post was changed and became a Warrant Officer's appointment.
My comment that: 'Major Sergeant was now doing a Sergeant Major's job' went down like a lead balloon with said officer.
I recall a chap called Flight Lieutenant Flight and a chap lost in a Shackleton off Kinloss whose given christian name was Major but whose rank was Sergeant.
O-D