Can't let this one go guys.
Having taught both FCs, Navs and AEOps on the SCC at Waddo I can say without reservation that they all bring something useful to the party. Without wanting to sound pompous, the UK Sentry fleet is the best in the world BECAUSE of its diverse manning structure.
As to the 'legitimacy' or otherwise of FC and AT brevets, these guys and gals do not get their BREVETS simply for 6 months work, they get them for 6 months work on top of the years of proffesional training and experience that has fitted them to their roles on the E3.
It is important to be aware that the job on the Sentry, while no harder or complex than many other airborne missions, is a very specific role, and as such, needs manning (in some areas) by people with different skills to more 'traditional' aircrew. Navs and AEOps do not have the skills for instance, to conduct AD ac control, nor CAS ac control, nor the direction of jamming and surveillance ac and (outside of the RN and possibly F3 fleets) only FCs have an in-depth knowledge of data links. They've been using them for 20 years. This is not to suggest that more 'traditional' aircrew do not bring other (equally valid) skills of course.
I fully expect people to reply with arguments citing VASTAC and FAC etc. These are not valid comparisons, and only further demonstrate the widely shared lack of knowledge about the Sentry's role.
FCs and ATs fully deserve their BREVETS, and are the only people for the job. Discussions about whether or not they are 'aircrew' are semantics and demeen us.
I have no vested interest in the success of either FC or AT branches, and fly a very different ac.