I dont know a huge amount of detail about him, but from what I do know, he was a talented man all around, both politically and militarily, and he took on both the Russians and the Taliban. He understoood perfectly from early experience, that assymetric warfare was the way to combat the Russians effectively and also that winning "hearts and minds" as the due process to make this successful.
Unfortunately he was assassinated. I wouldn't compare him with Napoleon, Caesar or Alexander, because they were conquerors, whereas from what I know he was more a liberator.
There was no doubt he was charismatic, determined and single minded in protecting his people. I would honestly compare him more with Washington on the basis that he had a knack for seizing the moment whilst retaining the belief of his people.
My two cents, anyway
Edit: He did also give a prophetic warning about problems that would arise for america and the world if they did not stop the Taliban, before his assassination and then subsequent attacks on America, iirc.