RRROOOOOARRRR!
As the enemy's concealed tunnels revealed themselves to daylight, along with the nightmarish horrors pulling chariots inside, the overexcited barbarians who had outrun their comrades skidded to a halt, gripped by terror. Thus exposed, these monsters would make short work of them!
Alas, it was too late to flee. These war beasts galloped far faster than them!
The other platoons, maintaining a semblance of formation at a safe distance from the front, didn't fare much better. It didn't take a master strategist to realize that three companies of green infantry like theirs would be minced by such a chariot charge.
In many ancient cultures, such as Ancient Egypt, the Roman Empire, Greece, China, Assyria, Babylonia, India, and even the Celts, relying on this Bronze Age-born technology was quite standard. Mounted cavalry, more versatile, had gradually replaced them much later during the Iron Age.