Thanks for posting that Pat. It's a very concise & excellent video demonstration I was trying to describe.
I know Todd. Long ago, he & Robbie both helped me learn that grip method. Over the years,, I have watched Todd teach shooting,, and I have found his methods & terminology to be excellent. I have copied a lot of his stuff, used it, and told him I copy his methods of teaching. That video is a condensed version of his instruction of basic shooting. But he is spot on,, and what he shows is what all the top shooters teach & use all the time.
Real combat,, you may not always be in a position to do the body presentation,, but the gripping method is still the same. If you are only using one hand,, then use it as correctly as possible. You have a much better chance of hitting a target if you do. I have seen Todd demonstrate this while on the ground, laying on his back, upside down. I have seen it in prone, and around corners etc. It works.
Blume, your issue with your finger comes from the fact you have shorter yet thicker fingers & hands. Not uncommon. I have taught people with different hand sizes a lot. I did a lady a few months back, who has real long, slender fingers & hands. Each hand size incorporates potentially different issues. But they can be overcome. This is where getting a gun AND it's grips to fit YOUR hands. I've said it here often,, get a gun to fit YOUR hands. And remember, "fit & comfort" can be done by matching the gun and grips, to you, even if it involves custom grips.
In a 1911,,, for hands like yours, slimmer grip panels often help a lot. If I recall correctly, you enjoy the Sig's. Look into grip selections & such.
Many gun makers are NOW building guns, and shipping them with a few grip options. Ruger does this some, as do others.
Once you find the best fitting grip design & panels, it can & will make a difference in accuracy.