I actually think this combat system is more realistic. Endurance and Health drop simultaneously. Think of Endurance as the amount of damage your body can take before getting knocked out. Consider it like Mike Tyson punching you in the head. You probably won't die but you probably go to sleep. If given enough time you will snap out of it and bounce back, maybe concussed but without any permanent damage a la Endurance. That said, if, after knocking you out, Mike continues to beat your face in, you will eventually die. The amount of beating it can take before this point is much greater than the amount you could take before passing out, but your body heads toward knock out/death simultaneously.