I haven't done any research with respect to the Murdock family.Geographical location may be the clue here to any connection.There are 3 areas in Georgia to where letters were written and received. 1) Paulding Co, Ga-where the wife lived when she received the letters from her husband
2)An area East of Marietta, Ga and toward Decatur(near the Davis Cemetery).This is where most of the family lived. It is from this area that James McClesky, the Captain of Comp M, Phillips Legion came.
3)Parkes Hardman lived about 6 miles away and in Cherokee County, Ga.
Also, it would be helpful to review the 1860 and 1870 census records to see how close together the families lived.