Most other areas? OL, Lb special teams.
When MM got here our defense was finishing around ~90 to 100 out of 113 D1 schools in most statistical categories. Worse than lots of G5 programs. Probably the worst program among all P5 conferences.
In year 3 the defense is much improved. Depth on the OL and at LB is still being worked on. ST was poorly coached and that was changed.