This entire post is people trying to debate game mechanics using real world violence. I'm pointing out they're doing it badly.

And yes, PCs are superhuman to a degree. That's why they have much higher ability scores and, in the case of the barbarian, a bonus to damage while raging. And when they do an unarmed attack, it deals 1 + Strength (+2 for Rage). For a commoner, that's 1 or 2 points of damage. For a level 1 barbarian, that's around 6 points. 1d4 + mods doesn't make sense and 1d6 is right out.

I suggested a bear because it has twice as much health as a commoner, so there's more space to measure. A .22 rifle can kill a bear, but it might take a few shots because of a low damage roll. And it's a fuck ton more likely to kill it than just biting it. 1 point of damage isn't a small amount. We just don't want to measure anything smaller.