My Pin(c)ney surname is spelled both ways on different documents. You must think about -who did the writing. Black people did not fill in information. Some, in 1930 still could not write and to spell their names, in what we think is correctly, was not something they knew how to do. But since YOUR Pinckney was found starting in SC-NC, anything is possible. I have confirmed names in Georgia, but it dead ends. I found a black well known singer with the surname of Pin(c)kney, who lived in a state on the East Coast. I can't remember the details now, because, when I sent information to their family historian, no response was sent back of any kind. So I dismissed it.
All we can do is keep posting, give true documentation evidence, and let the ancestors do the rest. It does get on the world wide web. I have seen a lot of my postings out there. So I am very careful what I say. You can't take back wrong made up information.