My guess in my last post hinting that the Hivites at Gibeon arrived from the southeast corner of Anatolia in the 12 century BCE seems to disagree with the notion that Hamor the Hivite is the founder of Shechem. The story in Genesis 34 puts this event in the time of the patriarch, Jacob, and long before the 12th century.
However, there was a proto-story behind Genesis 34. David Frankel thinks the proto-story did not include the violation of Dinah or the role of Levi and Simeon. See here.
I wonder whether the proto-story included “Hamor the Hivite”. There are a couple of other mentions of Hamor in Joshua 24:32 and Judges 9:28. These and Genesis 33:19, say that Hamor was the father of Shechem. But the “sons of Hamor” who sold land to Jacob do not include an individual named Shechem (in our edited version of Genesis 34 Shechem is the name of the son who fails to get affirmative consent from Dinah). So “father of “Shechem” seems to have originally meant someone who founded a dynasty there.
The LXX has Hamor the Horite. This reading is just as problematic as Hivite.
But the interesting thing to me is Judges 9:28. The best translation of that verse is probably the New Revised Standard Version because it does not try to harmonize with Genesis 34:
Gaal son of Ebed said, “Who is Abimelech, and who are we of Shechem, that we should serve him? Did not the son of Jerubbaal and Zebul his officer serve the men of Hamor father of Shechem? Why then should we serve him?
This means Jerubaal, Abimelech’s father, was once a subject of the “men of Hamor”. This would have been in the 12th century or so. So Genesis 34 may be projecting back into patriarchal times a 12th or 11th century situation. We know that back in the 14th century, during the Amarna period, Schechem was ruled by Labayu who claimed that his father and grandfather had preceded him. Thus Hamor seems identified with a later dynasty.
It is possible that Shechem was occupied by refugees from the north after the Bronze Age collapse. There is no story in Joshua about a conquest of Shechem. So one speculation is that the Hivites there joined the Hivites of Gibeon in making peace with Israel.