Well I certainly don’t view it as irrational and I don’t think looking at historical trends is the best way to look at it
Last season there were 13 1100 yard receivers and 3 TEs to do it.
Teams with multiple were:
Steelers
Chiefs
Rams
Those teams ranked 2nd, 3rd, and 5th in passing yards in the NFL.
In 2017 no team accomplished it and only 9 receivers total made it over the 1,100 yard mark
It’s not a small accomplishment and rather rare to have 2
Which brings me to my main point, the majority of Jarvis’ historical averages have come as the primary receiving option. I think as a #2 (over a larger sample size than 4 games) that average will drop. Mayfield has a lot of options and he likes to spread the ball around. Jarvis won’t get the volume he had over his career where he posted those averages. theres a lot of counters to that about better QB, different offense, etc but I’d be surprised if you didn’t agree that expecting 9 targets per game (his career average) over the last 12 games probably won’t happen
I view it as much less likely than a coin flip, but Vegas winnings/losings don’t go to RCF