A lot of their fanbase is really convinced that the real Mertz is the 20/21, 5 TD one from their first game. He and their receivers were knicked up the rest of the year, so I think he's better than he looked at the end of the year. And he's young so will still improve. But I don't think he's that good - that was a terrible Illinois defense that we just handed the ball to. 20/21 is crazy, but if you replace him with most other Big Ten QBs in that game most of them probably go 17-18 for 21. Chryst had a phenomenal gameplan, Mertz had couple very good throws and a lot of wide open throws to backs and the TE.
The other major Badger fan misjudgment IMO is the receivers. Davis and Pryor have made some excellent individual plays and have some experience, but I hear some fans saying they're one of the better WR corps in the conference which is absurd. They don't have a single 100 yard game between them, and honestly have each kinda stagnated. Davis went from 26/418/5 as a freshman to 40/418/5 (more catches, less efficient) to 30/250/1 and then missed most of last year. Pryor's career has been 13/179/1, 23/273/3, 23/278/0, and then not much last year. The #3 is Jack Dunn, who is the classic "gritty" player who you would like to see succeed but is just not that good.
The defense will be top 5. The OL will always be good, Mertz is almost certainly going to be better, the TE is a stud and I think the have 2 good backs this year (Berger/Mellusi) instead of half of one (Berger) last year. But the receivers are not scaring anyone, Mertz isn't Russell Wilson yet at least, and I don't think either of the backs are capable of carrying the entire offense like some of the guys they've had in the past. But the 247 guy is not alone in thinking this could be the year they dethrone OSU breaking in a new QB.