Marathonrunner,
I've noticed that you have made several negative posts regarding the P320 in the last few days.
You are in the minority of people that are unhappy with their P320's and perhaps your best option would be to sell the pistols you are unhappy with and move on.
Regarding bore axis heigth;
You mention that you are faster doing double taps with a G26. Can we assume then that you are shooting the pistol competitively and the extra .1 second or so has an effect on how you well you do in the competition?
However, if your purpose for having a pistol is for self defense, your comment about the G26 not fitting your hand properly makes no sense. If a conscience effort is needed when gripping the pistol is required, then in a crisis moment you will either spend extra time getting a proper grip on the pistol slowing the most important first shot, or more likely will grip the pistol as it comes from the holster and miss your assailant with both your first and subsequent shots. The instructors I have had regarding self defense have stressed the statement many times that "You can't miss fast enough".
My suggestion would be to use and train with whatever pistol fits your hand and points naturally the best.
BTW, I have a g26 and have trained with it and with the P320SC. My first and second shot times were not only faster with the P320, but were more accurate. The g26 requires me to reposition my hand during the draw to obtain a natural point of aim. The P320 fits my hand much better and overides the much touted advantage of lower bore axis, especially in 9mm.