To me, these schools are like the firearm training schools such as Frontline. A lot of money and excellent training but similar training can be had by joining good local clubs, and going out and trying things step by step. There is so much concerning survival that needs to be addressed. It starts with physical and mental strength. Both are enhanced as the training progresses but you have to be in good physical shape to begin and you have to have a mental toughness to match.
Working with 12-13 year old boy scouts has shown me there is a huge difference at that age. Whats that old saying? "It's not the size of the dog in the fight, it's the size of the fight in the dog that matters". It takes a lot of mental toughness to go on a limited diet for a day or two, let alone a whole week or longer.