There were apparently TWO related men who were each named Thomas C. Brown. One was a descendant of the John Brown in Culpeper Co., VA who married his cousin Elizabeth Brown (a daughter of Daniel Brown "II" and Elizabeth Coleman)....and the other one was a descendant of Daniel Brown and Frances Neville (who moved to Hampshire Co., VA). The Daniel Brown who married Frances Neville was a son of the referenced Daniel Brown "II" and Elizabeth Coleman, and hence, the Daniel Brown who married Frances Neville was a brother of the above Elizabeth Brown who married her cousin John Brown.
The above John Brown who married his cousin Elizabeth Brown strongly appears (from a LOT of research) to have been a son of Henry Brown "I" and Keziah Jones, a grandson of Daniel Brown "I" and Jane Copeland, and a great-grandson of the Francis Brown "I" who left his Will in Essex Co., VA in 1691/1692 (Francis Brown "I" was apparently married to an Elizabeth Cole, per one available record). The above Daniel Brown "II" who married Elizabeth Coleman was a son of Francis Brown "II" (left his Will in Essex Co., VA around 1708) and Elizabeth Allen, and a grandson of the above Francis Brown "I" (so the Francis Brown "II" who married Elizabeth Allen was a brother of the Daniel Brown "I" who married Jane Copeland....and they were apparently the only surviving sons of Francis Brown "I').
I suspect that the two referenced (and related) Thomas C. Brown have been "intermixed" in some records. Comments/questions? Note: As I recall, the Thomas C. Brown who was out of Hampshire Co., VA had a brother who was named Nathaniel Brown, and I believe that Nathaniel went to some other county in KY.