The point is that back then, everyone lacked many of the things that fanaticism would cause a society to lack.

Really? Consider trade -- a major factor in the society's wealth and survival for the last several thousands of years. The fanatic barbarians wouldn't trade, would they?

You don't think technology mattered before the Industrial Revolution? Oh, but it did. From bronze weapons to early firearms, an army with a technological edge had a big advantage.

Governance didn't matter in ancient and medieval societies? Do you actually believe that?