That's not as much of an improvement as you might think... Caesar was absolutely murderous and no stranger to ordering ethnic genocide either.. During the Gallic Wars, his armies butchered off at least a million and a half people, while enslaving a few hundred thousand others, partly for the crude sake of boosting Caesar's political career and paying off his debts. Paving the way for smoother Roman colonization was another benefit of this genocide. These things should remind you much more of Hitler than they do of Napoleon.

Bear in mind also that this was done without modern weapons and killing techniques. Hardly a humane ruler. That Caesar happened to be much more rational and erudite than the German dictator certainly helped his long-term image, but just because 2000+ years of history and some good political observations for posterity blot out the mass murder of civilians doesn't make it any less grotesque.