This is an excellent point. IU's offense absolutely has taken a step back after losing its QB, RB and left tackle to the NFL. We have depth at RB, a promising talent in our juco QB and young talent at left tackle, but the reality is that the offense is not near as good as it was a year ago.
The reasons for optimism, and why some think we could be better than a year ago, is that we look much better defensively after replacing d-coordinators (Brian Knorr was fired) and the overall depth of the program in Wilson's 6th year is to the point where we're solid in all phases even when front lines guys go down with injuries.