Sometimes the wills did give slave info, I've transcribed hundreds of them that contain showed quite a few slave names in them. But you are correct in wanting the Estate Records too, because that would give you an inventory of slaves as well as any distribution that was given even if it was many years after the death of the slaveowner. Of course, you won't find any slave records in an estate in the 1890's, but if you're looking for someone earlier, I urge you to look through the Probate records for wills and any other records for members of the family who may have passed down property & slaves to a slaveholder. One of the things I've been doing is transcribing the wills & estate records of a few surnames of known slaveholders of my family showing their distribution of slaves and I have been able to follow several generations of slaves back in time; these records I've also been posting on my County sites so that others can do the same for their ancestors.
Some of the County Probate records contain much more than wills, some of those will books have all kinds of court records,including land, administrative records, tax records, apprenticeships, bastardy bonds, for instance. I've been having a field day looking through the Warren County Probate records, I'm finding records in the 1900s court procedures that have given me the names of children of ancestors from the 1700 & 1800s which I didn't know about. Not all of the Counties have complete records, though, and not all of them have as good a collection, but just having these records available online at FamilySearch is a real gold mine for researchers.
As far as old Zeb Vance goes, one of the counties I host is Vance County, so I know about him, and have a couple of articles about him on the site, including a story that ran at the time of his death on April 14, 1894. It contains some biographical info about him and his family, so perhaps it is of interest to you, the link follows.
I do urge you, though, to look through the records on FamilySearch, under their North Carolina Collections, because they have quite a few databases for the State, and I do see they have some Civil War Pension databases, although I'm not sure what info is actually in them since I haven't really looked through them, sometimes their collections take you to another website.