Oh, I don't doubt first name changes at all. Even my grandfather changed his name to sound American, and he was born in America.
The Countess who lives in Rohrau isn't even a Harrach by blood, only by marriage, so your information isn't correct either. My father's cousin met with the Harrachs that live in Rohrau, but I didn't say he met with a Count that lived there. I think the Count there had died before my father's cousin went there.