Heidi Heitkamp, Jon Tester, Claire McCaskill, Joe Donnelly, Joe Manchin, Doug Jones, John Bel Edwards, Steve Bullock, ...? And most of them are Senators and not governors, which makes it even more significant/worse for Republicans. People like Hogan or Baker would never win a Senate race in their respective states.
Will lose, could lose, could lose, could lose, could lose, will lose, could lose, only narrowly won both times. 
I see no Democratic version of Baker or Scott (and maybe Hogan), who are going to landslide in hostile states during a hostile political climate. The last was Mike Beebe from 8 years ago. We'll see if JBE can do it I guess.
But yeah, you are right that Senate races are far more valuable than gubernatorial races in most cases.
I could see someone like Jim Hood or Billie Sutton become the inverse Baker/Phil Scott and be extremely popular if they were to win their initial races. The question is, if they will win this year and next though.
The electorates of MA and MD are more elastic than Southern electorates.
Before this year when it became obvious Hogan would win in a landslide literally no one would have called MD’s electorate “elastic”
well,it is a fact lol.. see 2002, downballot races, etc...
