I have noticed the same thing I have seen mentioned here a few times. Having a windscreen wrapped all the way around the pot, for Most of the pot height, yields outstanding heat exchange. I get some unreal boil times using about a 1/4 inch space between pot and screen, using my open country 4 qt and gravity mf stove.
I suspect all of these other weight factors can be factored in, things like windscreen, head space between liquid and top of pot, and lid thickness.
Regarding variable metal thickness, you are academically correct. In practice, it is reasonable to say that all equivalent quality and materials will be about the same thickness, for a given capacity. Yes I know snowpeak uses thinner ti than toaks, don't get lost in the minutia.
If beverage can durability works for you, only look at and compare beverage cans. The same applies if you will only consider stainless that can bounce off a rock without damage.
Regarding the most efficient being a water heater, I believe the camping version of that is called a Kelly kettle. For the just add water to bag crowd, it may be an alternative to the jetboil type pots.
Definite trends from these numbers, you are rarely well served by a pot that falls outside of the 1-2 range of diameter/height. Within that range, weight differences are pretty small, but that is the margin this community obsesses about.