This is still America so carry what makes you happy.
The "two spare tire" comment is innacurate, in this case your first gun is just that, your second gun would be your spare.
I don't think two is overkill be it guns, flashlights, knives, sweatshirts or any number of other things that I carry backups for.
But I'm primarily in remote rural areas, where if you didn't bring it with you, you go without.
My truck has enought cold weather gear to survive a breakdown at night in the sticks, some simple "emergency" type food, spare firearms, spare ammo, batteries, lot's of things I'll hopefully not need to break out. But if I do, it's right there.
When I was a kid I worked in a shop in Northern Arizona and drove the wrecker most days. I was amazed at the number of people I winched out of the snow, who were freezing, wearing t-shirts, (because that's all they had) and saying "we thought Arizona was a desert"!
I'll add that I'm a lot more likely to have to deal with a pack of wild dogs than a pack of wild humans, but in either case I'd rather have more than I need.
Not everyone is living in the same circumstances that you are, needs and requirements differ widely from area to area and person to person.
JTMcC