I may (hopefully) be able to give you some clarification on the Cloyd family snarl...which is a biggie.
First:The Jack Cloyd you refer to is, indeed, NOT Jackson Cloyd of Howard County.The John "Jack" Cloyd you are looking for is a 2nd cousin or something to Jackson.
John "Jack" Cloyd was born Sept. 8, 1806 and died March 8, 1890 in Kentucky.He married (1st) Mary O'Bannon of which he had a daughter, then (2nd) Victoria Williams and had a son, Robert.John "Jack" 's father was James Cloyd b. Feb. 21, 1762, Augusta Cty,Virginia and married to Rachel Tilford.He died c. 1836 in Cumberland County, Kentucky.James was the son of Ninian Cloyd who was one of the 3 sons of the original John Cloyd that came from Ireland.
Unfortunately, that is all the information I have on that part of the family.My own branch is directly from Jackson to Gilbert Marshall to David to John, Jr. to the original John.
Let me know if you would like any of that information.I hope this helps a little.