Generally speaking, only troops who follow orders immediately and resolutely are capable of the large-scale maneuvers needed for winning battles consistently. When orders are not followed routinely, a military unit becomes little more than a disorganized mob, incapable of implementing sophisticated battlefield tactics.
Though sufficient material resources are also crucial, no amount of resources can make up for a lack of battlefield discipline. Military discipline is widely recognized as the single most important factor determining military success. Legendary conquerors, such as the Romans, used discipline to overcome opponents with better weaponry and greater numbers. The British Empire is another example of an institution built on the foundation of unusually disciplined military personnel.