Perpetuating a myth

Scott Taylor, with the latest on the CDS speculation game, can't resist perpetuating the myth of a CDS rotation of some sort amongst the services.

"Although it was never set in stone, in the past, the post was rotated on a regular basis between the army, air force and navy officers. If that tradition were to have been upheld, an admiral would have served in Hillier’s place. Naturally enough, the slighted navy feels that after being jumped in the queue on the last go-round, it should definitely get its man in the top job this time."

Since unification, the order has been:

Army
Air Force
Army
Navy
Army
Air Force
Air Force
Army
Navy
Army
Air Force
Navy (acting)
Army
Air Force
Army

That's 7 Army, 5 Air Force and 3 Navy, with one of those an acting appointment. Let's put aside ridiculous assertions of some rotation and focus on the needs of the service.