I would think it better if a team is challenged along the way so they'd be prepared for a tight game against a very good opponent when the time comes.
It may well be, though there have been moments where they have been tested early in games or in the third quarter. For instance:
In the opener, we were down 10-0 and responded with 59 straight points.
In the Nebraska game, for instance, Horni threw a pick-six early in the third to make it 17 all. The team responded with three straight TD drives to end the game while the defense had two turnovers and pitched a shutout.
After a dumb turnover, Purdue had the ball in the redzone down 17-9. The defense promptly got an interception.
Against Indiana, we were down 10-0. We scored a TD on our first drive after that on our way to a 28 point victory.
This past week, we threw a pick six to make it 17-14 despite us having ten times as many yards. After the offense was stopped, the defense promptly got a turnover. Their next drive, they got a defensive TD.
This team is calm. Both times I've seen them in person, that's been the most impressive thing about them. They can beat themselves for 35 minutes and know that they are in complete control if they don't do it for the next 25. It's how you can be untested despite having 19 turnovers in 10 games. I have zero concerns about this team's demeanor. At this point, my biggest concern (by far) is the injuries on the offensive side and the resulting lack of weapons. But again, this team has a mentality that no matter what obstacles come up, they will find a way. There is something mentally specially on both sides of the ball that was definitely missing on the defense in the last set of great teams that we had (2009-2012).