In a life threatening situation you will likely perform a skill like operating a firearm at 40% of your typical capability. Alastar TDS-C does a good job showing how much your groups can open up at various distances using improper sight pictures.
It's helpful to see this demonstration- my takeaways:
- It's the muscle memory that makes this demonstration possible
- Training with a goal of perfection is useful to build that muscle memory
- Within the 7 yard self defense zone you can benefit more from speed and muscle memory (using an isosceles stance) than acquiring a perfect sight picture