To be honest if you get to the point where you are fighting then your self defense has already failed.
As for some of the MMA comments, I am 56 years old and train submission grappling once a week. I train at a level that is comfortable for me and have developed my game around my particular skills. If you can call being old and slow skills. I go with the old school Gracie style of fighting, or in my case rolling, not to lose. I play a very defensive game and allow my younger friends the chance to wear themselves our or get frustrated with the slowness of the game and to make a stupid mistake. You would be surprised how often this works.
As someone pointed out WSL's approach was survival also. His approach sounds very much like the H2H I learned in the Marines. Weapons of opportunity were a big part of our training back in the day and still is in the current program. As the put it now, "One Mind Any Weapon".
BTW James, its Marines, with a capital M. We jarheads are touchy about stuff like that.