In terms of identity, a single (offensive/defensive) "unit" for one season does not an identity make. I'd say the Illinois football program has established two true multi-year identities over the past 40 years:
(1) Quarterback U in the 1980's, inheriting that title from Purdue. For a very solid 10 years (Wilson, Eason, Trudeau, George, Verduzco) we really helped lead the transition from Bo/Woody's mantra of "3 yards and a cloud of dust" to a high percentage short pass offense, with a high completion % and 300+ yards of passing per game. Mike White designed, implemented and engineered that offensive philosophy in Champaign and other coaches followed.
(2) We then followed that up with some very strong defensive units that ran through the Lou Tepper regime and were anchored by exceptionally strong linebacker play ---- with Brownlow, Holecek, Howard, Hardy, Rice and others.
Since then, we've had a couple of good seasons and several really good players --- but we've had no consistency and we've absolutely lacked an IDENTITY. I believe BB is working to fix that.