I don't know of any connection between your Isaac ALEXANDER and my James ALEXANDER. None of the names that you gave are ones used in my line.
James' son, Reuben, left North Carolina to settle in Indiana by 1812. All of Reuben's brothers settled in Tennessee (near Rutherford County). Only his daughters stayed behind.
Some people want to lump all of these ALEXANDERS together as one family. I'm not convinced at all that they were one family. There was a huge migration of Presbyterian Scots to North Carolina in the 1700s and ALEXANDER was a very common name! (Sorta like Smith to the English )