Alexander the great, I think was a great military leader because, he was obstinate, he had a firsthand military education from his father, he was a military genius, he had a talent array of sub commanders and he inherited an army already willing to fight for him.
Alexander was extremely obstinate and had a habit of never letting obstacles stand in his way. This is proved by similar sieges on the north east region of India, in which he built series of wooden bridges of deep ravines to cross. This would have taken immense persistence to achieve. We also see this behaviour of never accepting an obstacle to be insurmountable when he in rapid succession captured once thought impregnable fortresses such as Aornus. Alexander's stubborn nature helped him to being persistent, never accepting an obstacle to be insurmountable, and this all helped him in being a great leader.
Alexander's father Phillip was seen as a top military minds of the ancient world, and alexander benefitted from this tremendous first hand military education.
His father, transformed a crumbling kingdom that was about to be overrun by enemies to one of the most powerful states in Greece. Alexander became a great leader because of his experience of a first-hand military education.
Alexander was on the whole a military genius, his ability to craft tactics, adapt his strategies to evolved circumstances was tremendous in making a great military leader. His ability to use tactics and strategies helped him overcome armies much powerful than his. He also successfully was able to adapt his strategies to evolving circumstances that the Afganistan region presented to him, and changed his army to deal with guerrilla warfare. His sense of time was deadly, seen with his decisive cavalry charge was highly successful. Alexander's intellectual capability...