That’s a fair question. I’ll try to elaborate my philosophy. Right or wrong isn’t the point to me, but I’ll share how I approach builds for Super Flex Dynasty start ups.
Firstly, there are always outlier players, but they are outliers for a reason. Good or bad.
IMHO it’s not that you do not need RB. They are definitely key. In a SF league, though, the QB is king in my opinion. They will routinely score more than other skilled positions and you can start 2. On top of that, a young QB has a far longer career (typically) than an RB does. Picking at least 1 early gives you a longevity for your dynasty team. As well, all of my dynasty leagues have deep starting rosters so you are running 3RB or 5WR. That’s why IMHO it takes time to hit that curve and I plan for it.
WR as well have a generally longer shelf life. Leaning into those positions at a start up builds a core that can be used for years. Plus some of the younger guys need a couple years to get their feet, but those years do not deminish their long term potential.
RB usually hit it running and then flame out sooner. They are one of the most replaceable positions. Look at 2020 and 2021 to see how often big names come out and reshuffle the list. Consider how hard it is for even good RBs to get that second contract. Consider why so many players draft the ‘handcuff’ for RB. Next man up is far easier than at other positions. It’s not that they do not matter, they just have a shorter window.
If you start your draft focusing on RB you are likely building a win now team. Nothing wrong with that. What I was suggesting is more of secure the long term QB (Lamar / PM / Murray / Dak) then smash WR. While CMC can help you, if the rest of your team is not ready then he is wasted points on your bench. If instead you build a team that is strong but not fully there, you can still fill in with your Gordon / Gurley / Bell type guys for a year or two while the rest of your team gets ready.
You can win with “older” players, but you are not burning their most productive years. You land them for the vet discount. Then even as early as next year go after the Harris / Etienne / Hubbard / Brown types to get that new RB with fresh legs to pick up the slack and your curve into winning form lasts longer.
You are correct in that those guys you mention are huge assets. To me top end RB are good, but they are only great for a win now build which is just not how I build. You are on in that there is nothing wrong with them and they can absolutely help your squad.
In that first round where those RB are going, I’m 100% on PM / Lamar / Murray / Dak (maybe) in a SF league as I believe their return will be greater and far longer. This is absolutely not the way it should be done, but it’s how I approach Dynasty SF start ups. I feel it let’s me use my draft capital better.
Again, though, that’s just me and my two cents!