Where did you pull this gem?
Perhaps a little review of Greek history would tell you about the Battle of Thermopylae. There are hundreds of battles across the world and throughout history were smaller forces not just beat but routed much larger ones.
Trapping a larger force and immobilizing it through its own numbers is a common military tactic. It was commonly done by the Confederate generals who almost always faced larger forces. Those larger numbers mattered not until controlled by a man capable of using them effectively.
You really need to learn about such matters if you intend to discuss them.