Given that Alexander was one of the most successful conquerors in all of history, he almost certainly benefited from being extremely lucky. If he had lived longer, therefore, he would have probably experienced much regression to the mean with respect to his military success.
Of course, once you are already the most successful conqueror alive you tend to need less luck. You can get by on the basic competence that comes from experience and the resources you now have at your disposal. (So long as you don’t, for example, try to take Russia. Although even then Alexander’s style would probably have worked better than Napoleon’s.)
Given that Alexander was one of the most successful conquerors in all of history, he almost certainly benefited from being extremely lucky. If he had lived longer, therefore, he would have probably experienced much regression to the mean with respect to his military success.
Of course, once you are already the most successful conqueror alive you tend to need less luck. You can get by on the basic competence that comes from experience and the resources you now have at your disposal. (So long as you don’t, for example, try to take Russia. Although even then Alexander’s style would probably have worked better than Napoleon’s.)