My guess is that Speedy had a CPO Cox'n - I had a brief sojourn in HMS Sabre in 79, and she had a Lt as Commanding Officer, a Lt as 1st Lt, a Chief ERA and a CPO Cox'n, who was normally at the helm entering/leaving harbour, and who was certainly in charge of the vessel. He was also a keen and capable cricketer and was on first name terms with the predominantly officer members of the RN team and committee.
I remember we had FOST on board one day and he and the Cox'n spent most of the visit discussing matches past.