Thank you. I know it may be kind of a silly question.
It's not.
You are looking for what combination results in the least front sight movement at the break.
That may be with trigger finger on the pad, or sunk further to the distal phalange. Obviously this depends on your hand size and finger length.
I would suggest two approaches:
1
Dry Practice: Using your hand size as a guide, select all Grip modules to match (e.g. Glove size medium, put the mediums on). Leave the retaining pin out.
Follow safe dry practice guidelines, and perform "wall drill" trigger presses, ensuring the sight does not move. Grip hard. No, harder than that.
Tip: wear a AAA headlamp and / or +1 diopter safety glasses to enhance your ability to clearly see the front sight.
Experiment, and choose a grip size combo that minimizes front sight movement.
2
Live Fire: Assemble the selected Grip panels, and repeat the drill, live fire. Watch for front sight movement. Re-evaluate the grips installed based on results. This may require several shooting sessions.
As a metric, shooting 'The Test' (10 rounds at 10 yards in 10 seconds) on an NRA B8 target will help to give you a score. You are looking for all 10 rounds in the black.
Tip: sometimes going +1 size on the support side Grip panel can help 'fill the gap' for your support side palm, so as to provide more surface area for recoil control.
The end result should be a grip backstrap and side panel choice tailored 'for you' and your particular anthropometry, based on minimum sight movement and objective shooting results.
Rich