I'm just not seeing it. I'm not saying he won't have value, but his ceiling is limited by the fact that at best he's #4 on the totem pole.
Assuming he starts, which is a debate of its own, your saying you don't see Peyton Manning taking advantage of a Jimmy Graham kind of athlete while coverges focus on DT, Welker, and Decker? At least enough to make him a top-12 TE?
The issue that I have been raising since the beginning has been that some people are allocating 270-3000-30 (or more) to DT-Decker-Welker while still slotting JThomas as a near the top TE (say top third in the NFL in terms of production). As I have already pointed out, that leaves bread crumbs for pretty much every other WR/TE/RB on the team, which just doesn't happen in real life. The only way that would have any chance of happening would be if Manning has one of the greatest seasons for a QB in history (if not the greatest).
This same phenomena happened last year when people were projecting Welker-Gronk-AH-Lloyd of the Patriots to have crazy numbers (like 275-4800-40 between them), which was also never going to happen.
My point all along has been that if if people want to slot DThomas with bigger numbers (which I am fine with if he is capable and wins the primary receiving TE job outright), then people will have to REDUCE the production of the superstar receivers. I DO NOT believe that the solution is to eliminate the production from the "other guys" while leaving the Top 3 WR numbers at an elite level. Something has to give, or else Manning will have to have a 5500/55 season to get the numbers that some people are projecting.
That is why I suggested that people make full projections, starting with a reasonable total for Manning and then reverse engineering a breakdown of how things will play out. Because if you start with the production of individual players, Manning's total will be inflated.
While people like to slot the mainstays on an NFL offense with the huge chunk of fantasy production, there ALWAYS are other guys that will get rushes or catches. Those guys will still get 10, 20, 30 receptions or 40-50 carries, etc. That's not going to change. What's going to change is the appropriation of production for the main players in an offense.
Take DEN as an example. Last year, the Broncos offense got 25% of their offensive yardage and 22% of their offensive TD from players not named McGahee, Moreno, DThomas, Decker, Tamme, or Stokley. That includes both rushing and receiving yardage. The non Top 4 receivers accounted for 126-1074-7. I would argue that on any team 20-25% of the production will come from depth players with limited fantasy value that are midway down (or worse) on the depth chart. That's why there are 53 guys on a roster. Similarly, teams don't only pass, so consideration needs to be given to coming up with a breakdown of rushing attempts and yardage.
So taking into account what is a reasonable expectation for Manning and taking out a reasonable amount for the "other guys" from that, that will leave the core of offensive production to allocate to the main cogs in the offense. That's how I would go about coming up with a team projection and offensive production breakdown.
Remember, the Broncos ranked 2nd in scoring and 4th in yards from scrimmage, meaning that they were already an elite offense. There's only so much more you can just tack on as additional production.