I'm not sure what post exactly you're referring to, but the Romans were soldiers, not warriors. Soldiers are trained in group tactics - that is, they are trained to rely on others to help them - while warriors are not. The Romans, often as not, fought warriors, not soldiers, and so, individually, were not any better individually. As long as the Romans have the room to cooperate, they will generally prevail, but stretch them a bit too much, and longer, slashing swords aren't going to be blocked by someone else's shield, and crowd them a bit too much and their shields begin to hamper their own movement.