Even if the offense isn't nothing close to what we have seen the last 4 years, it's still going to be a 40+ point per game offense. That I can guarandamntee. And if the defense does noticeably improve, while OU could have a lesser offense, it could be a better overall team. I'm actually not worried about QB next season, not with Riley around, and I think that Anderson will bounce back once again, although it make take him a few games.
Really, the biggest loss I would see on offense is if Brown departs, which is a distinct possibility. The good news is OU keeps getting a Broyles, Shep, Westbrook, Brown, etc. and next season, Lamb will be the predominant target and OU has some great receiver prospects coming in.
I guess what I am trying to say is between what he did with Texas Tech for a single bowl game that he became OC and then his work at ECU turning marginal QBs into very good QBs stat wise and with the resources he now has at Oklahoma, I have zero concerns about the offense going forward.
My biggest concern has been around the defense for awhile now, but it finally has a chance to improve.