If your goal is to reduce medical errors, create systems that don't depend on a single person's fluctuating energy level (e.g. have two doctors responsible for each patient, keep patient loads low enough that they can deal, automate as much as possible with computer systems (e.g. billing), and delegate to e.g. PAs for mundane diagnoses). Exhausted people make mistakes, can't work or think as quickly, are less creative, and are generally less happy. All the technology in the world won't help you if the key decision makers screw up at the wrong time.
After all, coffee does exist for those times when your natural energy level won't do it for you. ;)
Nonetheless, I don't think these guys are getting 4 on 4 off... I think they just work basically straight through for 12-16 (or more) hours and get maybe a day a week off.
I can completely sympathize though that 4 on 4 off would be incredibly hard in and of itself. I'm not sure I could do it for weeks let alone months on end.
I learned this primarily from my mother, who was a RN nurse anesthetist, and a doctor who became my father's primary hunting partner about the time I was old enough to start actively hunting.
There's no justifiable reason to give a large, urban hospital an organization system fit to the battle field.
So this is useful training, albeit at a cost. Although if they make a mistake that kills a patient during residency and learn they can't deal with the consequences of that, I suppose the earlier the better. They can of course move to less life and death specialties.