I don't know what stats you are looking at, but Fede's ACC stats are as follows right off Pitt's website for the 20 game ACC regular season schedule.
7.1 ppg
6 rpg
1.9 blocks per game
The biggest problem with this is, Fede's DR rebound rate was 13.5 for the entire season. That is bad for a center any way you want to slice it. In comparison, Hinson's DR rebound rate was 16. For Hinson, this would be considered barely to slightly above average for a power forward. For Diaz Graham, he was 17.2 for the entire year which is ok for a center. Its neither bad or good, but it is far better than Fede on the defensive side of the basketball.
The 2 worst defensive rebounders on our team by position were Nelly Cummings and Fede. Replacing Cummings with Dior is going to be a pretty substantial difference on the glass, and the word substantial might still be an understatement. Dior wants to rebound because he loves pushing the fast break offense off of those rebounds. Cummings defensive rebounding was non existent the last 7 games of the season.
Getting back to Fede, in his last 10 games of the season, he had a DR defensive rebound rate over 10 only 3 times in 10 games. That is painfully bad for a center whether you want to bring up the injury issue or not. He had a DR rebound rate of 8 or under in 5 of those games, which is Nelly Cummings level bad at rebounding and was one of the main drivers of why this team was getting crushed on the glass.