It took a little bit to get it all running right for the first tab, from there it was a matter of doing a lot of cutting & pasting & adjusting to set up the other capacities. The plots were a pain because each scenario had to be run manually for each hit probability and then the 63 results copied over to be used in the plots.
...carrying a reload or two...
I think the key is balance.
You need a reasonable amount of capacity to have a chance of making enough hits before you run dry. But having lots of ammo/capacity is only worthwhile if you have the time to shoot it all. You also need a good hit rate probability. But, again, even a tremendous hit rate probability won't help if you don't have the rounds you need to make the all the hits.
It's all in finding a happy medium. We shouldn't rely exclusively on capacity--we may not have the time or the skill to make use of those extra rounds. We shouldn't rely exclusively on our belief that our hit rate probability will be high in a gunfight. For one thing, it might not be that high, and even if it is, we still need need enough rounds available in order to be effective.
Really, that's really the story of self-defense and handguns in a nutshell. You need skill, and you need equipment and you need to find a balance between the emphasis you place on each. You can't substitute skill for equipment/capacity/caliber because if your equipment doesn't work/you don't have enough shots/you pick a caliber that can't do the job then skill can only take you so far. You can't substitute equipment/caliber/capacity for skill because the best equipment in the world won't carry you if you can't shoot well enough and run your equipment well enough to get the job done.
I did the calculations to satisfy my own curiosity. I didn't know how the results would turn out. When I saw how they turned out, I decided to share them so people could use the information to try to find their own balance of capacity and skill based on something a little more concrete than speculation.