Even with Alexander inheriting a war machine from his father Phillip, he managed to do something that was unthinkable in Greece: defeat Persia in detail. Even with a machine created by his father, having the gumption to take it that far makes him sui generis.
But he had to do much more than copy his father. He had to deal with logistics in a way that his father never had to. Alexander's war was as much about the logistics of supplying his army as about the battles it fought. He had to deal with large geopolitical aspects of the war, such as the need to win (or defend successfully) at sea, not just land, and he couldn't be both at sea and on land. Founding lots of cities to anchor his authority was a geopolitical technique that his father had not had to employ.
Sure, Alexander was his father's son, but Alexander's accomplishments are his own.
But he had to do much more than copy his father. He had to deal with logistics in a way that his father never had to. Alexander's war was as much about the logistics of supplying his army as about the battles it fought. He had to deal with large geopolitical aspects of the war, such as the need to win (or defend successfully) at sea, not just land, and he couldn't be both at sea and on land. Founding lots of cities to anchor his authority was a geopolitical technique that his father had not had to employ.
Sure, Alexander was his father's son, but Alexander's accomplishments are his own.