I do recall back in the noughties Max Hastings, following the incident with the Iranians seizing the RN Patrol Boat (I think that's what it was from memory), giving his verdict that aside from maritime and aviation related military matters, Navy and RAF Chiefs shouldn't be considered for CDS post, in modern times, as they weren't sufficiently military in their thinking.
Max Hastings can do one. In the last 20 years the Royal Navy has played a major part, alongside the other two services in all operations. Most Senior RN officers are fully indoctrinated and used to operating in a joint 'Purple' environment. Whilst I respect his ability to put words on paper, he has no experience of Military service, is just a journalist and therefore is not in a position to comment with any authority.