I think he has been a very good recruiter throughout his career. That is of course different than closing recruits and being successful at Illinois in particular, but there are valid reasons for optimism.
At the same time, he has been successful coaching talented, highly ranked recruits, specifically bigs. There is no much evidence pointing to turning diamonds in the rough into successful high level players. If he had done that, he would have been more successful in South Florida.
So despite all this "positionless" basketball, yada, yada, yada, much will depend on Illini significantly upgrading our roster and getting talented players on the court. Even next year, the reason for optimism is the infusion of talented guards, many of them who can play PG (not really positionless). As a next step, we need to seriously upgrade the talent level at 3-5 positions.