ND has built the lines very well. This makes them a 10-win team, which is the ceiling because of the lack of athletes in the secondary and receiver. Wisconsin comes to mind as a similarity.
Weis had a QB and receivers, but never built the interior lines, thus his success was short lived. This is why USC struggles. They always have the athletes, but no maulers.
Coaching issues aside, if this isn’t addressed, then it doesn’t matter who coaches, as you will never beat a team who has both the interior lines and the athletes to complement.