> Odd to have this as last name in France.

It's really not. Even without considering Alsace Lorraine, there is a lot of people with German origin in France. In general, it's very common to see people with family name from Spain, Italy, … And also from the old colonies / protectorate like Lebanon or Vietnam.

You should read up on the 'saxon' part of 'anglo-saxon'

spoiler: saxony is in germany