Again you're comparing Romans and Gauls. They.Simply.Can't.Compare. I thought we agreed on that.

What is funny is that you're putting them ahead of Persian army, as "more dangerous" opponents! Genghis faced much more diverse enemies, from steppe nomads to great fortified cities of China, but you're simply ignoring it. It's quite obvious you don't want to accept what doesn't suit your theory and it's getting quite tiring arguing with you... Have a nice day.