You can't convincingly argue it because it requires knowledge too far in the future. Who knows what would have happened a hundred years down the line? Maybe shortly after winning, Nazism would fall to another German political party. Maybe a Europe unified under Germany would be a more powerful Europe able to lead the world and avoid the missteps the USA has made. Maybe global conquest, despite short-term suffering, really does lead to the greater good under one government.

IMO it's impossible to say what the long term result of a German victory would have been.