In what way is he naive?
He played for Manchester United for nearly 11 from 96 to 2007 under the greatest manager in football history, coached the Manchester United reserves for 3 years under the tutelage of SAF. One failed experiment with one of the most dysfunctional PL clubs in Cardiff he obviously learnt a lot from, and 7 years coaching Molde in the Norwegian league. He's had international success with Molde in the Europa league, on top of winning all domestic titles.
This is his 12th successive year managing a football club, the last 9 months in charge of Manchester United.
Pochettino, Zidane, Pep Guardiola. All managers who had near non-existent experience before being givent he reins of some of the best football clubs int he world. Even Jürgen Klopp had a cushy start. Honestly most managers that are something today, were given a shot at managing a big time club after some reserve team, or very limited experience beforehand.
Out of all these, OGS is by far the most qualified to manage a football club based on his experience before taking over the club alone. (Not current day, obviously, Pep does have somewhat better current qualifications).
Is Naive meant to state that he does not understand the game, the club, the league, the players? He's been an intregral part of every aspect of a world class football club his entire career.
So I guess I'm just struggling to wrap my head around why he's supposedly so naive?