I wouldn't say we were overmatched by any stretch. However, our O-line has gone up against two inferior D-lines (I believe most if not all of the NIU d-line were 1st year starters). For those two games we gained a good number of yards on the ground, but we didn't dominate either d-line like we should have.
As for our D-line, I think they have been average and have some upside. The problem with only having them contain is it exposes a huge weakness in our secondary. To successfully run the Cover 2 & Cover 4 defenses it requires getting pressure on the QB, otherwise the WRs have too much time to find space.
Lynch was able to burn us a couple of times with the deep ball, Missouri State wasn't able to connect on the 1 or 2 chances they had. The teams that remain on our schedule (save ISU) will likely be able connect on those deep passes.
At this point I'd give the O-line a C- and D-line a B-.
Rushing for over for about 500 yards in two games isn't good enough for you? The mistakes that have been made, penalties, drops, and turnovers have limited the scoring but their line is doing just fine and will continue to improve. There have also been some RBs not hitting the holes like last week when Bullock tried a couple of times to outrun the d to the edge instead of reading his blocks.