Stevie Nicks, front singer for Fleetwood Mac? Awesome.
Stevie Nicks, solo artist? Not so awesome.
I can go on...Robert Plant without Led Zepplin, Glenn Frey or Don Henley without the Eagles, Paul McCartney, Ringo Starr, or George Harrison without the Beatles, you get the idea.
There's a reason why they were in a group first, then went solo later. The other way around? Not so much.