Malodery: What type of body armor are you going to wear on your head?
By the way, you would not be able to dictate whether or not I take the first shot or the first 6 shots. I would control my offense and tactics. We really are not talking about a game but rather a life and death situation where I would take all means possible to stop you and save myself. I'm sure, after the first impact, you would turn tail and try to run, if you were able.
To live through a gun fight, you need three things:
1. Skill
2. Deliberation
3. Speed
By skill, I mean you must have practiced using your weapon to the point of achieving a level that will mean you expect to produce accuracy and precision. In other words you are not just "hoping". Have you achieved that level?
By deliberation, I mean you must be deliberate/willing to pull the trigger without hesitation. Most people aren't.
By speed, I don't mean "quick on the draw". I mean you must have achieved the ability to waste no effort nor delay in your actions for any reason. And you must "move". How's your health and agility?
Lastly, have you ever been shot at?
Besides all that, the ultimate end point of your argument about the "futility" of trying to fight someone wearing body armor....must only be that you are saying "why bother". Just give up and die. And thinking about your family, or my family, or anyone's family in one of these situations is very relevant to this whole discussion. Are you willing to tell them, "don't bother to arm yourselves or expect anyone else to fight back with a gun, as it is just a loosing proposition"? That's the inescapable outcome of your argument about body armor and armed self defense.