I cannot provide a link to an official analysis of the training/instruction program of an elite military facility. What I can do is tell you of my own personal experience with it.
You mentioned the lack of regeneration and rest, and you are absolutely right. The idea behind the selection process is to completely maim you psychologically and put you to the test physically, so they can later build you back up as a soldier with the extremely intense memories binding you to your troop. Not only that, but you obviously become extremely attached to your military function. The whole notion of being part of the elite, having passed the selection process gives you a great deal of confidence, pride and trust in your comrades(since they proved themselves tough and resilient just like you). These are all positive features for a soldier, in fact, essential. These selection camps, be it hell week or boot camp, provide all the soldiers with an important common ground, a common achievement if you will. The feeling that unites us soldiers is very strong, and only this ensures a loyal and functioning team, especially under extremely unfavorable circumstances.
Which brings me to a second important aspect. The lack of regeneration is almost mandatory, because these selection programs must simulate intense ongoing stress that a soldier will face in combat. That is why they screw with your mind and play silly games, to make you feel like a tiny little piece of useless stinking garbage. They just want to see how far they can push you, and check your reaction. Sleep deprivation, hunger, cold, fear and constant physical and mental stress is the best way to achieve this.
Bottom line: These methods do not aim to get the best out of your body, they just filter out those men that can take it and not break. Some just do not cope with little sleep. Others get all kind's of physical problems when they work in the cold, don't eat much or cannot warm up properly. Just like not all knees and backs are made to carry around a 50 kg combat pack, and under circumstances, also a wounded comrade on a bar.
My physique has completely changed after 6 months of basic training. I don't have the same peak performance regarding condition (running), long jump, or short distance sprints. The difference is I can do those things under all circumstances. If you don't get injured joints or whatever, you become extremely tough and resistant, but not really a super-athlete. In military terms, soldiers like to compare themselves to machines. Always working, never tired. So their training regimen does work extremely well, depending on what you set out to become: Athlete or Soldier?