Here's my tuppence. I think the 56 ****er that I knew was another one <g> a bully certainly.
Years ago, a MEng pointed out the difference between officer aircrew and airmen aircrew: One read the Daily Telegraph, had 5 O-levels and applied for a commission. The other read the Daily Mirror, had 4 O-levels and applied for airmen aircrew. All because the Air Ministry placed different ads in different papers. They still do.
More later.
IMHO, aircrew are different because they have to be physically fit, have the aptitude to do the job and then undergo 2-3 years training before they become productive. They do not have to be overly bright hence the old 5 O-levels and later 2 A-levels.
Air Traffickers and Fighter Controllers are very similar to pilots and navs. They too need aptitude but do not need to be as ohysically fit. It is a truism that failed aircrew do not become air traffickers or fighter controllers.
Engineers may have aircrew aptitude but are generally cleverer. They generally need a degree and that goes for a few others such as P Ed, Ed, Medic, Dental.
The admin and supply generally do not have the aircrew aptitude and are often populated by those who are not physically fit or who are chopped aircrew.
Finally, addressing the pilot/nav divide. Again in MHO pilots tend to be instinctive, tactically aware and spontaneous. Navs, OTOH, tend to think more strategically. They can plan ahead and consider the longer term plan.
It follows that the Harrier shag has to do both! As indeed does the Jag guy. The Tornado has a shared load but the ME guys have a whole team to play with.
The aptitude, selection, training, job all mold the man.
Aircrew will take chances. Air Traffickers will stick to the rules and so on.