Miller was ideal to blend in because there are so many that are not related. This name change must have happened when people came to America, it was just normal to change names to make them sound more English or to get rid of umlauts. Fun fact: Most Americans wanted to send the Operation Paperclip Germans back after the work was done, but they were too useful for the CIA because they could be blackmailed with their wartime history. The CIA infiltrated DOJ and FBI to stop the prosecution of war crimes, and changed names and history of the more exposed Germans. Some even got jewish names and a "survivor" story, because nobody would search for a wartime history.