To the OP, you are not correct, Buncombe County's multi-site P25 trunked radio system does include simulcast sites.
To clarify, the RR database doesn't have a really clear way to indicate a simulcast site that's part of a multi-site trunked system. The most obvious way to know is the word "simulcast" included in the site name. So in this case, there are three "sites", with two of them (East and West) each being simulcast sites. That means, as trumpetman says, that each of those sites is comprised of multiple simulcast sites. How do we know that? Well, the best way is to look at the FCC license information for the sites.
If you click on the link for the West site from the System database page, it'll take you to the Site Details page. From there, you'll see several license callsigns listed, each of which is a link itself. Click the first of those, WQPL588, which takes you to the RR FCC license page for that callsign. There, you'll see that the callsign covers 6 specific locations (7 and 8 are area locations for mobiles and fixed bases). Each of those 6 locations includes the same set of frequencies. Therefore, for this site, there are at least 6 separate transmitter locations, each licensed for the same set of frequencies. That's the indication that this is a simulcast site within a multi-site trunked system.
Again, just looking at the RR system database page, this detail is not immediately obvious. From a scanner's perspective, a simulcast site is programmed no differently than a non-simulcast site - therefore, the database listing only shows a single set of frequencies per site. We're not going to list each individual transmitter location with identical frequencies- that would be redundant and unnecessary. So, you either look for and trust the word "simulcast" in the site name as your indicator, or you drill down into the FCC license information and verify it for yourself.
For your other question, I'm not very familiar with other trunked systems in Western NC. If you consider Cleveland, Mecklenburg, or Catawba Counties as part of Western NC, then those are counties that run simulcast P25 systems. The Mecklenburg County system, more commonly called the Charlotte UASI system, is a multi-county, multi-site system that include simulcast sites, each with multiple transmitter locations. Haywood County runs a NXDN trunked system in the VHF band, but I don't believe it's a simulcast system.
At this time, I do not believe that any of the VIPER sites in Western NC are simulcast sites. The only VIPER simulcast site may be in the Releigh area, but someone else with more specific knowledge can verify that for you.