Let's get real here...it is not exactly rocket science these folks are going to have learn. Rank alone has nothing to do with one's ability to learn and perform.
The tasks the poor ol' Army guy/RAF guy/RN guy has to learn to crew the back end of a Chinook, Merlin, or Lynx hauling people, internal or external cargo is pretty simple.
Specialized tasks such as running Anti-sub equipment and the like does take extensive training.
Perhaps there is some turf protection going on here?