The question of hours is much the same as in the 60s. In the Navy we were rapidly expanding helicopters so the requirement for instructors meant that a lot became QHIs after only one tour. As Shy Torque #10 says, there were plenty of "incidents"" during mutual training as the boundaries were pushed (the Top Gun mentality meant you tried to be better than your buddy). That is why you were accepted for military training in the first place - fly the edge of the flight envelope or the opposition would. Typical annual hours in the FAA were 2-250 hours p.a. until the Sea King arrived. In the 70s there were multiple fuel crises and non exercise we were limited to 10 hours per month of which 5 were night. Not good if you were on a small ship in crowded European waters!
Military flying can never be 'cost effective' until called on for real so is always subject to budget restrictions. We can use simulators to save costs to maintain some handling skills but only the aircraft ever provides "experience".