I am not dead certain about your going back to Van Wert & Mercer Co., OH Hartzogs, but I think there is a good chance of it.I found a Lawrence Ray Hartzog b. 7 Sep 1915 White Co., Arkansas in an Ancestral File of the LDS family history library.He is the son of Joshua Byron Hartzog who was b. 3 Feb 1866 Washington Twp., Paulding Co., OH.This Joshua is the son of Joshua Hartzog, who is the son of Christian Hartzog who was b. PA and lived in Van Wert & Mercer Co., OH. Christian is the sib of my ancestor Solomon and both are sons of J. Georg and Salamarina or Salome Hartzog, immigrants from Germany to PA.
Karin King & C.J. Andes have the most info. on this family.They're tops!
I haven't stumbled across anyone from the Hartzogs in the south, many of whom descend from a different Hartzog immigrant than ours.