It's great hearing from you!I received an e-mail notification that you responded to my original message.
I agree that it is perplexing none of Samuel's children named any of their sons Samuel.It is hard to explain, but like you, I do think the family we've found in Madison/Garrard Co., KY is Samuel's family.
By the way, I think I have figured out where the land that Samuel Alexander owned upon his death is located.The executor of Samuel Alexander's will was Samuel Pickens who I believe was the father of Israel Pickens, an early governor of Alabama.There is a memorial marker for Israel Pickens located in Cabarrus County (about two miles east of the Mecklenburg County line) on Hwy 73, which states that Israel Pickens' birthplace was two miles southwest of the marker.This happens to be near or on the Rocky River, and very near the Poplar Tent Presbyterian Church.The land that Samuel Alexander purchased from John Dysart and was later sold by his widow Sarah Alexander shows a description of 167 Acres on the Rocky River adjacent the barony line and in the Welsh Tract.
Having found this area is very important as other Alexanders that lived in this locale include Nathaniel (I think an early Treasurer of the Poplar Tent Presbyterian Church), Daniel Alexander, and Moses, Jr., all sons of Moses Alexander, Sr. who died in 1762 in Cecil Co., Maryland.It's interesting to note too that one of Moses Alexander's daughters (Ruth) married a Dysart.
On the other hand, I am finding that the family of Jacob Nichols and Agnes Locke who were living in present-day Iredell County, NC in the mid-to late 1700's may have purchased land from one of the sons of James and Ann Alexander (this is the same James Alexander who died in 1753 in Rowan County, NC).I think the Jacob Nichols family is somehow related to Daniel Nichols who married Mary Alexander in Madison Co., KY in 1790, but I can't say for sure how at this point.
Unfortunately, I don't know how James Alexander who died in 1753 in Rowan County, NC is connected with the family of Moses Alexander who died in 1762 in Cecil Co., MD and I don't know for sure if Samuel Alexander actually connects to either of these two (seemingly) different Alexander families.