The problem is one needs to have the skills drilled in very early in flight training, so they become "part of one" as subconscious as breathing. More importantly, one needs to have emotional response (fear, flight or fright, startle, whatever the term of art used) wrung out of one's personality concurrent with the base skills. Once embedded, those skills will remain with less required maintenance, if you will. The primary skill USAF UPT taught was confidence in all kinds of scary conditions. MPL training in simulators are highly unlikely to suffice.