People act as they train.
I have read posts from people who were involved in real world shootings. The basic understanding I got was nothing they practiced was ever like what really happened.
I do believe training can save your life, and training is much better than no training. Maybe it will give you tools that you can use if you think yourself through the situation.
While shooting arts give people confidence, the best survival tactic is not to put yourself in a situation where you might have to use deadly force.
If I'm not shooting, I'm reloading.