I think you have misunderstood my point. And I don't appreciate your "think now." I know exactly what he is doing, because I have trained it from both sides.
My point is don't just stand there and think you are going to draw and shoot. Begin moving. AS you take your second step you should be acquiring your grip on your weapon. By the third or fourth, you should be shooting. But, you are also maintaining some distance. Don't backpedal, take off at 90 degrees from his line of attack, and as he adjusts, so do you. Run one foot in front of the other, like humans are designed to move.
Whether you move or not is absolutely NOT irrelevant. If you stand there, you will get cut. IF you move, you have more of a chance of getting good shots on him before he can close the distance.
And what commands? If he has a weapon and charges me, I am not going to waste time with commands.
I can prove that the 21 ft rule is BS, IF you know what you are doing, as I have said. I have an airsoft, and a training knife. I'll give you 21 feet, and bet you I get 5 or 6 shots on you before you get to me. I did it, repeatedly, just last month. And I'm not going to stop moving, so those shots are going to start taking a toll.
The 21 ft rule was born on a square range with someone whose feet were glued to the ground. And please, don't start with matches and IPSC. They may mean you are a decent shot, and I dont dispute that, but they mean nothing in a real world encounter.