Sure, but in both cases, the act was named after the musicians (Ted Nugent, Eddie & Alex Van Halen), and not after the lead singers (Derek St. Holmes, David Lee Roth/Sammy Hagar).
Well, yeah, Van Halen is the name of the band, as well as the surname of two musicians. VH had very steady membership, with 2 lead singers. And many people went to see them to see David Lee Roth or Sammy Hagar.
I just have no idea whether Nugent’s band has the same continuity of members, and I could not name another member. Didn’t his backing band used to be The Amboy Dukes?
Sort of. They didn’t start that way. The first few albums they were The Amboy Dukes. After several years Nugent was the only original member and he changed the name to Ted Nugent and The Amboy Dukes.
The lead singer of Bob Kuban and the In-Men was Walter Scott Notheis, who met an unfortunate end at the hands of another member of a love hexagon he’d gotten caught up in. Kuban was the drummer, and still performs per his Wiki article.
Steve Martin & the Steep Canyon Rangers might count. A lot of their songs do feature vocals, and Steve is the lead on some of these, but not enough that I’d call him the group’s overall lead singer.