All in all he did a wonderful job.
Before he took charge, Leeds regularly finished in the bottom half of the Championship, and were also in the bottom half in terms of possession stats.
He literally turned many of the same players who struggled to string together multiple passes before he took over, into part of the the best passing outfit in the division by far. Plus of course more importantly results instantly improved.
His stubbornness, insistence on a thin squad, plus injuries proved to be too much in the end. In quite a few of their Premier League games, including ones that they won last season, they started with 5 or 6 players that were already at the club before he joined.