This is demonstrably false.
OK my dudes. Play nice. I'm here to save the day with my amateur data investigation.
(Don't hate me. My sophomore at Iowa just got an internship with an insurance company big enough to be located in the most well known street address in all of Iowa, and he has inspired me.)
I am somewhat skeptical in the value of evaluating "NFL draftees" as a metric to begin with.
I also think you're both wrong....and both right. The devil is in the details. So, let's do a deep dive, shall we?
85 players drafted since 2000 (which counts guys who played one full year under Kirk Ferentz as head coach)
38 offensive players
1 kicker
46 offensive players
Offensive player totals.
WR-4
QB-3
RB-2
TE-11
Linemen-18
The distribution between skill players to linemen seems statistically expected. There's way more linemen.
However, the 11 TEs is undoubtably statistically significant. One, it's higher than probably any other team in recent history. And two, it would...in theory...limit wide receiver chances. Fair enough. It's college. I think it has always been a shrewd move by both Ferentz (who clearly knew the value of the TE from Fry, I didn't do Fry's numbers). I'm good with overperforming TEs and average, or even slightly below average WRs.
I was a bit surprised by the distribution between offensive/defensive players. You would expect it to be balanced (which it is....not too terribly off from 50-50), but not if you believe that Iowa doesn't produce good offenses. I very much believe they do produce good offenses. At least up through a certain point. The distribution though, is clearly fronted weighted on the time axis. Meaning, something has changed.
2000-2017
23 Offensive players drafted
WR-3 (.176/year)
QB-2 (.117/year)
RB-2 (.117/year)
TE-8 (.47/year)
Linemen-15 (.88/year)
2018 onwards (counts players who played at least one full year with Brian as the OF)
8 offensive players
WR-1 (.1666/year)
QB-1 (.1666/year)
RB-0 (0/year)
TE-3 (.5/year)
Linemen-3 (.5/year)
Statistically, Brian is as good (or better) with QBs as any OC under KF. Same with WRs and RBs. Course, the marginalilty is quite high with so few being drafted, but I have no problem saying they're AT LEAST comparable. Even in terms of QBs. I would say they're probably not out of line with the averages of most other mid-tier FBS teams. Hard to say on TEs, a little more data there. Hard to not give Brian his due and say he's marginally outperforming KF historical era, but I'm sure he's outerperming the FBS and maybe like his predecessors, all of college football.
Linemen though? I would argue a 40% drop is significant.
So, just to check and make sure he isn't due some credit for potentially inflated numbers in preceeding years of players drafted during his tenure as OL coach.
Offensive linemen drafted:
2000-2012: 13 (1.0833/year)
2013-2017: 3 (.75/year)
Nope. He underperformed by the metric of "sending tons of guys to the NFL" as their immediate coach, and is not responsible in any way for previous higher averages. He is underperforming in "sending tons of guys to the NFL" against the historical average under previous offensive coordinators.
In fact, he's miserable. By any measurable metric, except two. Which is, he is in the black when it comes to attracting players in the portal. And this is a metric I do not take lightly and fully ready to credit him for. Then again, we've only got 2 years of this data.
The other, as InGoodCo rightfully and wrongfully often points out, is wins. It's rightful in evaluating the program, and even Kirk Ferentz under those metrics. And yes, you can argue his choice in OC contributes to that. But only part of it. And, there's no way to evaluate what the performance would have been without him. So, we can only evaluate Brian on his data, and I believe there is enough data to do so.
My personal opinion, based on data.
Kirk's great. Always has been. Always could be.
Brian is not great by any measurable metric except the two I noted.
Brian is the problem. Kirk is not. But will become one if this continues to play out as the data suggests. College football is at an inflection point. Iowa is at an inflection point. Kirk, and other powers that be, will become the problem if they don't solve the immediate problem of Brian.
Full dislosure:
My data came from Wikipedia.
And I eyeball counted most of it. The numbers could be off by a player or two. Which could make major differences. But, not in the data that really matters.
Also, my math could be wrong. I'm not good at this. I'm just inspired by my kid and the value of data. I probably should have worked harder at math and got into this racket of data science.