There's more than one. In fact, other than the Rams, I don't think any of these teams are great.
Carolina is definitely not legit. They did play solid against Bad Jameis, but their other two wins are against the Jets and Texans, who are both in another category of bad. I don't see them finishing .500.
Denver is also not very legit, although they do have a solid roster besides the QB position. Bridgewater is a very capable QB, too, but I just don't see him stacking up against elite QBs. They might surprise and win 9-10 games, but I think they'll be lucky to win 8...they've also beaten up on horrid teams.
Las Vegas (still feels weird to type that) is still not a great team but a pretty good one. They'll be on the playoff bubble as usual. I don't know if they're legit by that definition, but they're still a solid playoff contender and not a championship contender.
Arizona is also not so great. They won on a last second shanked field goal by Minnesota and struggled to beat Jacksonville. Murray is is the most overrated player in the NFL...one of these guys who gets a crap ton of yards and stats but also a crap ton of negative plays to negate them, resulting in an offense that's not much better than average. I could see them losing their next three @LAR, SF, @CLE.