It's always the same with Hughes: when he takes over he has them playing what David Cameron would call "robust" football, then after a few seasons decides to ditch that in favour of expansive football - only for a total disconnect in the side, as the attacking players don't track back while the defensive players don't push up, and they become remarkably less resilient as a result.
The exact same thing happened at QPR.
I don't think that he gets teams playing robust football, but takes over sides that normally do so.
Warnock and Pulis were in charge before he took over at QPR and Stoke, for example.
Hughes takes over solid, aggressive, organised sides and adds goods footballers to them, due to his contacts in the game.
He relies on the players that are already at the club to provide a good defensive base and the new additions add some quality.
It works well in the short term, as it gives his teams good balance.
The things that are there when he takes over don't last over time, though.
He doesn't coach defenses well and the solidity and tenacity disappear as he fails to keep up the coaching that put it there.
Then the teams become frail and easy to beat, which negates any additional quality that they might have.
He's still relying on players like Whelan, Crouch, Walters and Shawcross for graft and grit and most of them are getting on a bit.
Shaqiri, Arnautovic, Allen, Bojan (though he's gone) are capable of playing very, very well, but they need a platform to do so.
It's just not there any more.