Little boys 9 to 14 years old won wars in Rome, they also lost a few. Learn about the real Rome in my book Legacy Grapes of Rome This video demonstrates what is in my book Grapes of Rome Legacy (the early Roman Republic), how children were used in the Roman Republic for war, and usually succeeded.
In a real battle, the second line while using their shields would stab, not slash the attackers. The Roman children would walk over the dead or wounded attackers finishing them off. The third line, while using shields, would have long spears and stab at the attackers in the front. It was a deadly wall of death. Others used this such as the Greeks and Persians, but not to the extent or success of Roman children. This wall did not retreat, it constantly moved forward. So when you see muscular big guys in the movies doing this, remember in real life the first three lines in a cohort in any formation were little boys, usually 9-12 years old, but in most cases, 10-11-year-olds were used.
The big guys came in after that, or if the little boys were killed, and only then.
Although these boys are not actually using Roman footwork (except for one), you can see how even the weakest of them become a deadly force. The two men would have been dead in seconds and the cohort would move forward, killing thousands of the enemy. Keep in mind although they were the best, over fifteen hundred years, hundreds of thousands of children were killed.