I almost hate, really HATE, to wade into this as I'm sure to be seen as negative, but I really don't understand the point of the exercise.
To my view, handguns have a purpose. They're designed to be carried readily available on the person to be ready at very short notice to respond defensively to a close-range direct personal threat. To that end, they form part of a system that includes loading devices, spare ammo, holsters, pouches for the spares, and so forth.
Further, they have a specific manual-of-arms that defines how they are most efficiently loaded, carried, and deployed.
The system and the process work together with the firearm itself to allow a defender to put rounds on target in a timely manner.
You could test many finite facets of the system if you had reason to. (Mechanical accuracy, practical accuracy of the shooter with that gun, draw speed, splits and transitions, reload speed, ease of carrying, weight per round carried, etc., etc.) But in the end, none of that matters in comparison to the overall question of which gun gives the shooter the ability to make enough hits, accurately enough, quickly enough.
Starting with an empty gun and empty mags defeats the purpose. It isn't relevant to how one USES a sidearm. Might as well ask which platform puts most hits on target if you're blindfolded, or your hair's on fire, or the guns are encased in blocks of lime jello, or you're stuck in a car trunk with a butter knife and a badger who just ate all your ammo.
Testing the ability to shoot 100 times or 50 times or really much over a reload or two doesn't help matters, either.
How about you just start with the load-out you'd normally carry, and some real-world threat scenario and compare how you do with each gun, using the guns you'd have, loaded with the full complement of ammo you'd be likely to carry, and let the chips fall where they may?