I second Swordmaster and Masamune on this. I've always been under the impression that Nobunaga's success had less to do with winning brilliant victories (battles like Okehazama notwithstanding), than with his overall strategic vision & ability. It seems to me that the commander who manages to consistently create favorable conditions for himself (via superior forces, supply, position, etc.) is just as intelligent and successful as the general who achieves victory via brilliant/unorthodox tactics, and Oda is a good example of the former.