Generally I am pretty high on the whole first tier of running backs. I think Derrick Henry and Zeke Elliot will disappoint a bit and I worry about Saquon Barkley's situation. That being said I expect them as well as CMC, Cook, Kamara, Jones, Chubb, Gibson, Harris, (Barkley), (Henry), (Elliot), Mixon, Ekeler and Taylor to all do RB1 things, in that order.

These are the ones for me:

1. JK Dobbins: This is a classic example of me loving a player but finding situational factors worrisome. I think Dobbins is a top 12-15 talent and I think he has legitimate top 8 upside. That being said, I don't know if I trust the Ravens to use him enough for that to happen. As a long running sucker for Ravens running backs dating back to the days of Justin Forsett, Alex Collins and even the infamous Buck Allen, I often find myself being frustrated with the RB usage the Ravens deploy. With Lamar Jackson, the NFL's best rusher, and Gus Edwards, one of the better backup RBs in the league, I don't know if I see a clear path for Dobbins to realize his potential. One thing I will say is I don't think the Ravens have had a back as talented as Dobbins in a long long time, so if the coaching staff changes their ways, it'd be for him. You would be banking on the Ravens allowing him to do his thing more, using him more in the red zone and using him as the featured receiving back. I think the last point will be true, but I don't know about the others.
2. Chris Carson: Carson is a beast. Plain and simple. That being said, he has dealt with a plethora of injuries in his short career and he has a very violent running style that often doesn't lend itself to durability. There is another factor that worries me about Carson: other offensive talent. The Seahawks are building a very formidable receiving room, with a growing superstar in DK Metcalf as well as the reliable Tyler Lockett who just signed a big contract as well as D'Wayne Eskridge in the 2nd round of this draft. On top of that, and probably the biggest concern to me, is a finally healthy Rashaad Penny. I think Carson is better than Penny. However, Rashaad Penny hasn't taken a hit to the body in almost two years and has first round pedigree. He can do it all and has flashed great talent before. On top of that, Penny is in a contract year and could very well be run heavy to preserve an under contract Carson and oft injured Carson. I don't expect Penny to surpass Carson, but it would not surprise me in the slightest if we see a much more even split in an elite passing offense to begin with. I don't see Carson's usual floor or usual upside.
3. Trey Sermon: The 49ers are going to produce high end RB2 level rushing stats at the least. However, we don't necessarily know who will be the one to capitalize off of that guarantee. In Raheem Mostert, I see someone that deserves to be touching the ball as much as possible. He is electric with the ball in his hands and can take it to the house on any given play. At this point, I see Mostert as a clearly better option to Sermon. I don't see Sermon as particularly special in any given area. The biggest knock on Mostert is his inability to stay on the field, and while I agree with that, there are two things I will say to it. First off, Sermon's ADP is rising and I don't love banking on an injury and for a rookie to take the starters place at such a high cost. On top of that, even if Mostert does go down, experienced rushers Jeff Wilson and Wayne Gallman seem to be in the mix too. Even though it is the amazing 49ers, I don't see a clear path this year for Sermon to be a star. I think he is one of those players that breaks out a couple years in.
4. Mike Davis: I like Mike Davis. He was one of my favorite backups for years and he runs hard whenever he plays. That being said, I am not in love with him as a starter. I don't see him as a great talent and I think he will be reached on often in drafts this year. On top of that, the Falcons defense worries me, as I do not see much promise outside Grady Jarrett and Deion Jones. That caps the gamescript, and I can see this offense turning to the passing game much more so with Calvin Ridley and Kyle Pitts. The thing most going for Davis is behind him is rather shaky competition. I think a starting RB with little competition is a commodity regardless, but I don't see him as someone that offers much in the way of upside and I would probably prefer to pass on that tier of RB to go other positions.
5. Myles Gaskin: Another player that I root for as a player, but don't see a special talent. I see a starter, but I don't see one that should demand all the work. In Salvon Ahmed, I think the Dolphins have a potentially better receiving back and one that could challenge in that area. In Malcolm Brown, the Dolphins have a serviceable short yardage back and goal line vulture. And all signs point to the Dolphins using a RBBC. I think Myles Gaskin will be a fine flex, but I don't see much in the way of a part 2 of his breakout nor do I see someone that will consistently put up RB2 numbers.