I wasn't surprised; its competition at 6:30 pm on WUPA here in Atlanta? The news!
Feud competes against the news in that slot in New York and does just fine.
And you really don't know how to count because just by looking at the host list I found at least double your estimate, and that's panel members alone. (Certainly several had to have Got a Secret or where mystery guests on top of that.)
Carson hosted "Who Do You Trust?" shortly before the Tonight Show, and Whoopi was center square/semi co-host on Hollywood Squares (Tom Bergeron). Alec Baldwin (current Match Game reboot) co-hosted in 2010 with Steve Martin, so that makes it four.
But Celebrity Name Game will go down in history as the only show to have
eight closing logos, as opposed to four on the animated "Back To The Future" (which they showed on a quadruple-screen).
Maybe CNG should've considered moving production to New York -- where the more popular late night talk shows originate from nowadays -- instead of axing it.