An afterthought - In 1784 Peter Wirey (aka Wirick) and widow Barbara (Teter) Hinkle were both living in John Wilson's district. Barbara would soon marry David Harman and they would sell David's North Fork 90a to Peter. (David would join Barbara on her deceased husband's property).
It could be coincidence in that David Harman might have advertised his parcel to the public. It could also be coincidence that there was a young male named David in Peter's household. However, there was a pattern, particularly among the Germans, to sell land within the family (including extended family).
No postulation of relationship is being made. The question is being asked and it might be worth keeping in mind when working Peter Wirick.