Paul, how much time have you spent as an Instructor? The Navy does a blend of Partial task Trainers, Simulators, full motion simulators, and aircraft training to get the skills to "take" in the prospective aviator. It's a reasonably successful training model. (And in the T-6 syllabus the Navy and the Air Force put together, the USAF does something very similar). The Army does something like that at Ft Rucker.
There are things you can do in a sim that you won't do in an aircraft due to the chance to crash it.
There is no way to develop air sense without flying in an aircraft, and since I've flown and taught in both fixed and rotary wing, I'd say it's more pressing a requirement in rotary wing.