To whom does Keegan compare Alexander the Great in Chapter One? What is the outcome of this comparison?

Keegan compares Alexander to Napoleon, Attila the Hun, Genghis Khan, Prince Charles, Hitler and others. While all of those military leaders made great strides and accomplishments throughout their careers, none can match Alexander the Great. Even those that came close had the benefit of tools and information not available to the Macedonian that covered several continents beginning at age sixteen.