It seems to me that a few days in the academy with a personal instructor would teach you much more about dueling than an hour or two on the battlefield. Getting to be a top-notch fighter would probably take much longer if all you did was fight battles than if you spent all your time with a private instructor.
Not that I don't think that a bit faster gain fro fighting battles might not be worthwhile.
But having trained swordfighting for one character to the limits of the academy, I have to say that it takes LONG time, and a LOT of money. The number of people actually have the time and money to do that is probably pretty limited.
