I have been thinking a bit more about why if "feels wrong" to lump 2 competitions into one. Consider the position that since there is only one set of results, in reality, only one competition took place. Only one shot was taken at each target. Trying to extrapolate a second set of results from that, is where it's going wrong.
I accept that there is a small element of luck in the sport, but at the UKAHFT level, most competitors put a lot of time, effort and money into competing. The whole point of a competition is to try and win, so it's a bit more than a light stroll and plink. Let's have a easy and fair scoring method that everybody understands.