I've had DNA testing for me (Ed Fischer,Vermont) and it opened up a whole range of 4-6th cousins, at least with 95-96% of confidence and one with 98%. Very few of them had the appropriate surnames of Fischer, Deutch, and Szollosi in common with my more immediate ancestry. I may go back for more detailed DNA testing.
Religion is also a factor, Judaism is more common in my family though individuals have intermarried into Catholic families and vice versa. Most of my Fischers are Hungarian, though the name was spread throughout the Austro-Hungarian empire and Germany.
You are welcome to checkout my family tree or email me at firstname.lastname@example.org
. Let me know if I can be of any help, it can be pretty confusing.