I'm no so sure about the others. The damage may be terminal, but a determined fighter can keep on long enough to drag you into the grave with him.
I'll grant you the stomach and the kidneys are less immediately deadly than the rest, and less optimal targets, but I suspect that a punctured lung would take you out of a fight real quickly.
Aside from the pain, which adrenaline helps with, you have now blood in the lungs. This causes choking and shortage of breath relatively quickly. With the increased heart rate from the adrenaline and exertion, as well as potentially labored breathing to begin with, I think a lung would limit you to one strike after being punctured before you coudn't effectively function anymore.
Also, the groin, due to the artery that runs through there (I forget which one) is one that will cause you to lose blood at an alarming rate. A deep stab to the groin and you'd better be at the hospital if you're going to be saved since there's no place to turnicate and you can bleed to death in a matter of minutes. Sure your opponent may get off a couple more strikes with decreasing power and focus, but if you've recovered you'll likely live.
Of course all this is suspect until we get a few willing volunteers. But I will grant you that the liver/kidneys/stomach are sub-optimal targets.


