What about when Patterson was good last year?
Michigan was 8th in the league in receptions, 4th in the league in Percentage, 9th in yards per game. 5th in average reception yards.
[For clarity, were those Big Ten-only numbers (somewhat SOS-adjusted) or were they BigTen+OOC?]You make a fair point. Still, I'd argue that "counting stats" for passing are somewhat underwhelming here because, in 2018, Michigan was run heavy by identity (and the offense was mainly built as a ball control unit to play off the defense which was #1 nationally until ... the last two games). Counting stats would similarly underwhelm if we were to judge the run games of
Big XII air-raid teams by comparing their total rushing yards to 2018 Illinois (second best in the Big Ten in rush yards per game). In both comparisons, counting stats ignore efficiency and the ability to succeed when it counts.
The first sign of that, in the statistics you posted, is how Michigan's receptions and total yards numbers cluster so far below the cluster of comp% and "average reception yards" (though I'm not sure what you mean by that -- is it avg rec yards per game? per attempt? per reception?).
Now: Your intuition is somewhat fair. I'm just acknowledging the confounding variable: that we'd expect Michigan's offensive identity in 2018 to largely explain its (passing) counting stats on its own.
Now if you were to look at that and argue: well, then why are blue-chip WRs even signing with Michigan? Well now you've asked an interesting question. Of course, until nabbing DPJ, Nico, Black, and Oliver Martin in one class, top flight WRs really hadn't picked Michigan. Not appreciably, at least, since Mario Manningham and Adrian Arrington followed Breaston/Edwards/Avant.
In sum, whereas I disagree that the counting stats are a useful way to judge these receivers, I agree that the evidence to claim that DPJ, Black and Collins are *certainly* the best in the conference is necessarily weak.
I'd also make a different point, that for Michigan, receivers this good are a "use 'em or lose 'em" proposition. Use them, or access to the guys I mentioned plus Cornelius Johnson will dry up. Top end WR's are probably the singularly least durable aspect of Michigan's recruiting prowess.