You are already one generation ahead of me, so I cannot help with your primary question.I am writing this to let you know that just posting the question the way you did has helped someone else!!I stumbled on your message while searching for data on the Ann Gantz who married Daniel Slifer.Now I find that her name was really Nancy Ann, forcing me to go back and re-examine some stones that I have already turned over once.
Is it fair to presume that you got this list of Nicolas' children from estate records??
Is it likely that your Nicolas Gantz was a brother to the David Gantz, born 31st August 1787, who married Eve Fahrney, born 17th October 1793 at Chambersburg, PA??David's youngest son, Emanuel, born 28th June 1826, married a Margaret Slifer who was probably a daughter of Daniel and Nancy Ann Slifer.