I think way to much is made of this because people don't like the results. It is way more about having the athletes to run the offense than it is about changing what type of offense is run. Our offense is not that much different than what Ohio State runs. Are they having to adjust to the B1G? Our offense isn't a lot different than what Penn State runs (though it wasn't as effective last year). Are they having to adjust to the B1G? Our offense isn't a lot different than what Indiana, Purdue, or Minnesota run. They are pretty competitive in the B1G.
The problem isn't that the offense won't work in the B1G. It has been shown that it will work. Other teams have shown that it will work. We were a very respectable #25 in the country in total offense in Frost's first year here - when he still had enough Pelini recruits left to field a legitimate B1G offense. We should have been absolutely terrible that first year before he could adjust anything if the problem was he needed to adjust to the B1G.
The problem is we didn't recruit one complete set of offensive players in a four-year span. We only recruited two WRs that contributed in a five-year span. We only recruited one serviceable RB in a four-year span. We only recruited three legitimate OL in a four-year span (maybe four if Sichterman pans out) and one of those started out as a TE. You simply can't strike out that much and expect to field a legitimate Power 5 offense.
Frost does carry a little bit of the blame for not turning it around a little faster but he was hindered by some bad luck (or whatever you want to call it). He managed to pull two RBs who were legitimate talents in two weeks in Washington and Bell but both turned out to be head cases. Then it definitely hurt that he struck out on WRs in his first full class. The rest of his first full class looks to be filling in nicely, it's just taken them awhile to get on the field. Wan'Dale was a legitimate WR but he clan wasn't patient enough for the rest of the offense to catch up. Johnson and Thompkins still have possibilities at RB. Piper and Benhart were already starters last year and Banks looks to be in the mix this year. Plus McCaffrety was a great chance to take on the heels of Martinez. But all of those guys were only into their second year here last year and didn't get anything resembling a normal off-season. That's basically as many contributors out of one class - in two years here - as we got out of the previous four combined.
Frost had to change his offense because of the personnel he had. UCF led the nation in deep throws in 2017. That's been severely lacking the last two years because we haven't had the receivers to make it work. And when you aren't a threat to throw it down the field, there's not much room to open up everything else.
So Frost definitely has adjusted his offense. But not because of the B1G. Hopefully it's back closer to what it's supposed to look like this year.
I don't like the results. You are 100% spot on. I do think that Frost has changed the O to meet the B1G. Going after bigger OL. Going after bigger receivers with a larger block radius. RB's who can bang between the tackles. He went after what he wanted the 1st 2 years. Smaller track star receivers. Shifty Duck R or whatever that position is. The B1G simply fed him his lunch. And I hate that. He's adjusting. And rightfully so. I think some of his concepts will remain the same, but as you mentioned (having B1G style players) we will have much more success.
OSU is and will always be the B1G. They are loaded with blue chip kids. Whatever system they run will work. And comparing us to Indiana, Minny and Purdue is not really a resounding claim to the acumen of Frost and Co.
I'll agree our recruiting thus far has been horrific. Too many misses. Head cases, non-contributors, transfers etc.....When we are trying to rebuild that is really hard to overcome.
Even with my negative posts, I do see some positives. I agree with the OL. They look to be solid and have gotten some depth and guys to stay put. The TE's look good (better w/Fidone) and WR's have a few guys who played and some potential. Concerned about the RB's TBH. I really like Sevy and Yant. His size is intriguing. I know this is about the O, but I have to give props to Chin and the D staff. They have gotten some good depth and quality across all 3 levels (again I'd like it better if Honas was a go). The aggressive play of Williams and CTB got the younger DB's some meaningful snaps

. The fact so many came back for another year speaks volumes IMO. Not to the degree, but I am hoping for the same passion exhibited by Peter and Wistrom (Peters/Winston/Frasier). The D culture has taken effect and I think we see it win 1-2 games this year. They'll have to be solid out of the gate until the O catches up.
lastly, I think having Lubick calling plays (split w/Frost) should help as well.
This staff came to NU after 2 years together. And came into the B1G with some legitimate stromg coaches, coordinators and staff. There was (and is) bound to be learning curves. The B1G is just unforgiving and a hard place to learn on the fly. Frost is learning. And that's a huge step.