Any person who wears the enemy uniform is a legitimate target. The Nazi in uniform on the front lines and the one in the rear cooking meals that hasn't fired a rifle since basic training.

Any person who gives aid to the enemy or pushes enemy propaganda is a target too. Julius Streicher never killed a Jew but because he published a newspaper which attacked the humanity of Jews making it easier for people to mass murder them he was found guilty at Nuremberg and executed.