It's "truthy".
At least in the USAF, our pilots are in some cases hugely over-trained, given far more information, tactics, doctrine, etc., than they could possibly need in any one type of fight. That means when they enter into a REAL fight which never ever ever matches the training scenarios or pre-planned doctrine, the pilot can make it up on the spot *and win* because he's using nearly 100 years of inherited experience to guide his actions. Sometimes when placed in a set training scenario against an opponent who has trained with just one tactic for that specific scenario, the American fighter pilot will struggle to match his opponent's precision and execution. But mix it up a bit, and the American fighter pilot's performance goes waaay up compared to any opponent following an inflexible doctrine or using precise pre-planned tactics.
I think the same logic is applied across all of our military services. Train our military to be flexible by feeding them tactics, doctrine, strategy, and then place them into training exercises where the measure of performance is success, not how precisely they followed the book. That breeds operational flexibility and effectiveness, and then the really strong swimmers are encouraged to write doctrine for the next generation to ignore
