He is doing a good job there but I have the feeling if for example he stepped up a level again to work for a club like Spurs (only an example) he would fail again.
He better remain where he is and what he must do is to be able to replace some of their most wanted players and others who are getting older, their problems on the last seasons has been to remain in the Premier League, they will remain for next season but no one knows if they sell a Palhinha type of player or Mitrovic and some other players who already are veterans if they are competent enough to keep recruiting at the same level.
One thing that made the difference this time for them is that he actually got almost all their signings right, unlike their recent seasons on the top tier, and that isn't easy to do for a club with their recent history in the League.
I got the feeling every player signed by them he always gives his opinion, won't be surprised if he stays there that he will sign some players from Brazil, by the way Andreas Pereira and Willian worked out very well for them, and they were interested in André of Fluminense, a good player.