This sounds like a Mr. Monk thing, having to have even numbers or something.
Well, I've got five, six, and eight shot revolvers, but I've also got semiautomatics that make me count to seven, eight, ten, fifteen, and eighteen. I think it's my having studied music, and percussion in particular, that makes that easy for me. One gets used to whatever number of beats there are in a measure being repeated, and whatever number that is, that's what it is, whether two, three, four, five, six, seven, nine, twelve, or whatever. There's a song in Jesus Christ Superstar that goes, 1-2-3-4, 1-2-3, 1-2-3-4, 1-2-3, over and over like that. So 1-2-3-4-5-6-7-8 isn't that big a deal. I like that eight shot N frame .357, by the way.