Phillip II of Macedon revolutionized the Macedonian army and warfare in the Ancient world. Phillip II made military service a full time occupation which allowed the men to train constantly and become a cohesive group. He also innovated the phalanx technique by introducing new weapons such as a longer spear and a two-handed pike.
I think the question you are going for right now is, Why was the macedonian army so successful?
The Macedonian army (if you want to be specific, the Macedonian military under King Philip).
Gorilla Warfare - Dad's Army - was created on 1974-11-29.
He was a Macedonian Greek whose army conquered Persia.
His job was a commander of an Macedonian army. He doesn't have an empire.
He ruled by harnessing his Macedonian nobles, ruthlessly slaughtered those who opposed him, and used the loyalty of his Macedonian army as the core to his conquering sequence.
Granicus
They simply were not prepared
The army King Porus had elephants as part of its centre. It was an army of infantry and cavalry, with the elephants as the equivalent of today's tanks. The elephants were held by the pikes of the Macedonian phalanx, and separated so that they could not break the whole Macedonian line. Some were turned back on their own troops and broke them up, some passed through the Macedonian line and were dealt with in the rear.
Under Philip II, Macedonia became a powerful State by the middle of the 4th Century BC BCE. He reorganized Macedonia's army and is given credit for developing the battle formation known as the phalanx.
The Macedonian army, allies and mercenaries under King Alexander the Great.
The American team in Modern Warfare 2 is the United States Army Rangers, simply called Rangers in the game.