Well, when someone says "more German than the Germans," it means that they are really, really German. But what does it mean to be German?
Being German means you come from the country of Germany, and there are a few things that are associated with that. Germans are known for their efficient and organized nature, as well as their love for beer and sausages. They also have a rich history and culture, with famous composers like Beethoven and Bach, and important events like Oktoberfest.
So, to be "more German than the Germans" means you embody all of these traits and qualities to an even greater extent. Maybe you are always on time and have everything planned out, or maybe you really love sausages and beer and have tried all the different kinds. It's a way of saying that you really embrace and embody German culture and values.