These are brothers of mygreat grandfather, George Benjamin Adair (Sep 10 1871-Jul 24, 1902).
They're sons of Benjamin Adair, Jr, b. 1788 in Laurens Co, SC, and Nancy Martin, b 1802. Jane Elizabeth Whitehead Adair is their mother. She is most likely the daughter of George W. Whitehead, b 1801.Some records show her as Emily.
A fourth known brother is James Lewis Adair b. 1877.
The 1880 Hackneyville Every Name Census Index has many Adairs listed, and this family is listed 2185-2189 on the index of 2263 residents. It's easily available, and can be saved as a PDF. It lists several Adair families in the Hackneyville area, but omits families in the Pinkneyville area.
Other related Adairs are buried in the Dillard cemetery, and many more at Smyrna Primitive Baptist cemetery nearby in Coosa Co just over the county line. I have photos of many of the graves. Where specifically did you find these graves? I'd like to check them out when I'm up there next.