Southern tier of PA is tricky. The “Midlands” is a reasonably fair description ideologically, but since many of the economic and cultural ties were to the south beginning in the early 19th century I wonder if “Tidewater” or even “Greater Appalachia” would be the better fit.
The latter would square with the “Pennsyltucky” and “Pittsburgh and Philadelphia with Alabama in between” descriptions sometimes offered.
Greater Appalachia probably works best for me and from what I see in South Central PA ... less Harrisburg. But I'd have to say there is a lot of overlap on the map and it has a lot to do with where your family originated and assimilated.
My father's side of the family were mostly Highland Scots and some English. I can trace one lineage to Jamestown, but the vast majority came from Scotland later in the 1600's and went up the Cape Fear river into North Carolina. A few were prisoners of the crown and were basically indentured servants. It was either that or go to prison back in Scotland. It was only during the great depression that my grandparents and father came to PA. The rest of the family remained in NC. My mother's side of the family immigrated from Finland in the early 1890's. They settled in northern MN.
So I have roots from Yankeedom (MN), Tidewater & The Deep South. The Yankeedom moniker doesn't work at all for my family in MN. They are Lutherans, not Puritans. They are dairy farmers that cleared their own land and carved out a living. The Tidewater description in the article is weak and it could apply to anything. I identify with the deep south from a state's rights perspective and I identify with Greater Appalachia since I value individual liberty and I am “intensely suspicious" of "Yankee social engineers.”
All of that said, I am only a first generation Pennsylvanian (Midlands, where "Government intrusion is unwelcome, and ethnic and ideological purity isn’t a priority.") I will go along with the government intrusion part, but ethnic and ideological purity are very important to me and I tend to tie the two together.
Conclusion: it is a neat exercise in think about what make you and people around you tick, but I would place Colin Woodward closer to an astrologer than reporter.