Yes, I do recall seeing information about this particular William. Recognized that list of children. However, we were never able to figure out if he fit in with the descendants of Samuel and Ann Holmes.
They had a son named William who died in 1813. He was the son of Samuel, and I assume he would be considered "Sr." Any "Jr" in the court records would not necessarily mean that Jr was the son of Sr. That was simply a method to distinguish between men with the same name. It might be father and son, but it might be a man and his nephew, or two cousins. The older man would simply be Sr.; the younger one Jr. Later on, when Sr. dies, Jr. might step up and become Sr., and another Jr. would appear. I have had that happen with this same family.... with all of the Samuel Holmes men.
I wish I could point you in the right direction, but this was one of the big questions we were never able to answer. If you have any other questions, or things you'd like for me to check, please do so.