I actually came across this post researching from the other direction—trying to find an Alexander Smith of Johnston Co. who married a Rosser.
I have an Alexander Smith, son of Samuel Smith (1709-1783) & Edith Whitfield (1717-1785). After Samuel died, he willed Alexander his plantation on MIDDLE CREEK, Johnston Co.
Then in 1803, Alexander Smith, James Rosser, Elijah Rosser & Faddy Whittenton conveyed 421 acres of land lying on MIDDLE CREEK to John Eason.
This made me wonder what the connection was between Alexander Smith & the Rosser family. Did he marry a Rosser?
And that's when I found your post. Certainly something to explore further!