Anita....I don't know how much help I can offer at this time, but a Thomas Brown of Lunenburg/Mecklenburg Co., VA married a Mary Pettus, and as I recall, one of Thomas and Mary (Pettus) Brown's children (or maybe grandchildren....I would have to check) married into the Cluverius Coleman family. I strongly suspect (albeit, no proof) that this Mrs. Mary (Pettus) Brown and "your" Thomas Pettus were closely related. Also, I believe that Cluverius Coleman was a witness or surety on the Mecklenburg Co., VA Will of the referenced Thomas Brown.
From just some brief "internet research," it seems clear that Cluverius Coleman was a member of the same Coleman family that "traces back" to the "early" Robert Coleman "I" who married Elizabeth Grizzell, and their son Robert Coleman "II" who married Ann/Anne Splisby. My mother's Brown family....that was in Essex Co., VA in the 1600s....also married into this same overall Coleman family, but it is not at all clear if the above Thomas Brown was a member of my mother's Brown family ("Brown" was/is such a common name). As a matter of fact, there is a living male Brown DNA donor who shows his lineage back to the above Thomas Brown, and that donor does NOT match the DNA of the many male Brown DNA donors who are in my mother's overall Brown family. I was never 100% convinced, however, that the referenced "non-matching" donor had/has his lineage "traced back" correctly....but who knows?
In any case, I would be at least mildly surprised if the above Cluverius Coleman, James Coleman, Ben Coleman and Mary Coleman were not ALL part of the same overall Coleman family....but it would take some additional research to attempt to prove or refute Mary Coleman's "connection" to that family. If I find anything definitive on that Mary Coleman, I will certainly pass it on to you. Bill