Syracuse kept an extra blocker in and the Clemson DL was not the factor they usually are. The 'Cuse put up 23, Texas AM 26, and South Carolina 21 in the first half. The Irish will score in the mid to high 20's.
The Irish defense will be fine. Unless you think the Texas AM defense (held them to 28), Syracuse defense (held them to 27), Boston College defense (held them to 27), are better. I would name more teams but all they played was crap. If three 3 teams held them to 27/28, ND will hold them to 20.
Go watch a few of their games.