This. You figured out what eludes many shooters, especially new ones, because they rigidly adhere to "rules" based off outdated shooting techniques.
You should use as much finger as you need to ensure a straight, rearward trigger press that lets you keep your sights properly aligned throughout the motion. I too was initially taught what the NRA curriculum teaches -- that you should only use the finger pad -- which isn't necessary wrong, but I quickly found that not all gun/hand combinations are ideal to allow for that, and using the finger pad alone may not allow for enough leverage for a good trigger press in other cases.
There are only two fundamental things that should be emphasized - trigger press and sight alignment. If the sights don't move as you press the trigger back until the shot breaks it does not matter how much finger you use, or if you use a stick or a bic pen. Throw away the useless pie chart that gets posted around; it is meant for one handed Bullseye shooting, not a two handed grip and it it just confuses people, especially new shooters.
I personally like the following chart: