John Barton-4442 is son of Isaac Barton-330 and Keziah. He is born about 1765, but they didn't marry until 1772, so something is not correct, either his birth, their marriage, or they are not his parents.
That John has a son Isaac Barton Barton-4398, who married Nancy Snow, but that is not the profile that is identified as Isaac Barton II. That profile is Barton-1803 and is son of Isaac and Keziah. It looks like Isaac Barton-4398 is a 'cousin' of Isaac Barton-1803 II. The profiles have different parents, different birth and death dates. Isaac Barton-4398 was born in SC, Isaac Barton-1803 II was born in Tenn.
William Green Barton-4872 mentioned in your question is the son of Isaac Barton-4398, which is not Isaac Barton-1803 II.