Lemberg and Prague WERE german Cities, however after World War 2, the Germans were kicked out of most countries and forced to move to the post world war 2 boundaries of Germany. The german Cities of Danzing and Konisgburg became the Polish city of Gdansk and the Russian city of Kalingrad
In Fact Prague was the capital of the Holy Roman Empire until it was moved to Vienna
German city does not mean it was a part of Germany. Austria is a german country yet is not part of Germany (Except during WW 2) Lemberg and Prague were part of Austria-Hungary