Let's go with the 26 RBs in first 3 rounds. I have 10th pick and I can have Megatron I take him. Likley Forte and Ridley there maybe McCoy. Bryant, Julio and Green all out there also. The nuts on the table pick is Graham at TE. Nuts on the table is what guys in our league when some is not afraid to go out of the norm picking.
Now when third round comes up choice at RB will be very slim. Couple of the following guys will be there Rodgers Brees Brady Peyton Cam Ryan and couple of the wideouts I mentioned. Those are top value not the 24th running back. Even in flex scenario you can hammer the wideouts to play the flex spots. At running back you will have to look at goalline guys, backups to injury prone number ones and work the waiver wire for backs. But you will be set at your other spots unless injuries hit.
I have played 23 years and I love seeing guys chase a position it rarley works. Owners still chase kickers from time to time why chase the 24th RB when a top 5 WR is on the board?
Agree completely. Grabbing Bradshaw, Mendenhall, Lacy, etc. when QB1s like Brady and Ryan or WR1s like Thomas, Jones and AJ are available is chasing the RB run at the end of the run. I like to start runs, not finish them. The comment above about waiting until the first 11 QBs are gone ignores the reality that guys like Brees and Rodgers, according to my VBD spreadsheet, are going to outscore QB12 by as many points as ADP is going to outscore RB15. That same difference is 20 points more than the difference between RB8 (end of round 1 RB) and RB24. Sometimes people don't realize that the top QBs can outscore QB12 by more than the top RB can outscore RB12 and the bottom of the RB1s will outscore the worst RB2s.
I think your ADP comparisons are a bit off. Bradshaw, Mendenhall, Lacy, etc. are 5th-6th round RBs. Brady and Ryan are fair comps as they have 5th round ADPs, but Thomas, Jones, and AJ are 2nd and 3rd rounders by all ADP measures I can find. So, your actual WR options are more like Wallace, Antonio Brown, and Torrey Smith, who few consider elite options.
Additionally, QB1 and QB2 may outscore QB12 by as much as RB1 outscores RB15, but they're priced accordingly, as 2nd round investments. QB3, 4, 5, 6, etc. aren't likely to have as great a VBD lead over QB12, so to get that big advantage, you need to give up a top 5 receiver or a top 15 RB. To connect that to your first point, sure, take Rodgers in round 2, but then you just might be picking from Bradshaw, Mendenhall, and Lacy after all once you get to the 5th and 6th since you no longer have a need for Brady or Ryan. I'd rather have Chris Johnson or Reggie Bush and then take Ryan, as you recommend.
You always have to sacrifice something as you build your team. QB appears to be the easiest position to sacrifice this year; both QB and WR are deep, but you only need to find one QB.