There will be a lot of 'po-faces' around the other 2 services and our very own fast-jet pilot community
Anyone with that much 'concern' clearly needs a busier day job and doesn't know what Joint even means. Just let the inter-Service rivalry go ladies and gents - it isn't welcome in today's Armed Forces and many who question the choice aren't privy to the criteria and reasons that SofS applied in choosing the candidate.
Sir Stuart is an excellent choice for CDS IMHO. One of the sharpest, if not THE sharpest, minds in Defence.