The Carolina backcounty in the 1700s is pretty much a dark hole for researchers -- no church registry records of marriages and baptisms such as one finds in Charleston. We begin with the 1790 census which offers as many questions as it does answers. Who were all these people in such & such household?, or where are all the people who should be in such & such household? Who is neighbor to who?, or did an unusual path or track used by the census enumerator on horseback make seemingly neighbors not really neighbors & vice versa.
Land records are more forthcoming about who lived adjacent to who, and these records should be consulted more often -- more often than ancestry lines touted by WFT, LDS, or DAR which are often based on family stories and/or non-contemporary bible records. The placque(?) at Raburns Church is one such example, that now infamous paragraph on Abercrombie ancestry that Karen Roberts attempts to dismantle in her book.
Anyone foolish enough to take this Colvil speculation to the bank is just that, foolish. That said, I do think that speculation is worth listening to. Naming patterns are important, very important. But the lack of SC birth records means we do not know the names of all the tiny babies put in early graves.