Here's what I saw last night in Indiana's surprisingly powerful first half against Ohio State (I only saw the first half):
IU's offense looked a lot like our offense in 2015 and 2016. A lot. Same no-huddle, same spread, same look and feel everywhere. Two big differences were, (1) Vols had a decent run game those years, which IU was totally missing last night, and (2) IU's QB was very good at hitting the middle-distance throws with consistent accuracy and touch, which Josh (God love him) just wasn't consistent at.
So same offense, same look and feel, differences came mainly from player abilities: we had Dobbs and Hurd and Kamara and Kelly running, they had no one much...on the other hand, they had Legow throwing, we had Dobbs.
Otherwise, I think you saw Mike DeBord being the same OC in both places. He was simply adjusting his play calling to make the most of the strengths of his players.