The truth is nobody knows how this is going to go.
Walsh was 2-14 his first year in SF, Vermeil was 5-11 with the Rams.
A couple of years later both teams won the Super Bowl.
Vermeil was known at the time as a respected coach who couldn't win the big game, losing to the Raiders in SB XV.
That's similar to Rivera in Carolina. He made the team respectable and took them to a Super Bowl and lost to the Broncos.
He could show better OR worse here.
People talk about SB wins, but from what I see many SB coaches like Jimmy Johnson, George Seifert, Mike Shanahan often fail in their next gig.
Meanwhile a lot of coaches fail in their first job and end up learning some lessons and winning in their next stop.
And if Joe Flacco and a one-armed Peyton Manning can win the Super Bowl there is no reason a player with Haskins skills can't mature and take a team that far.