It actually amazes me that the guy who implemented Guardiola's system on the pitch the most is unable to implement even a lesser (since less talented players, that's acceptable) version of it right now.
This wingers glued to the touchline shtick gave success all of 1 month this season
Because Managing is completely different to playing, even on a tactical level.
Pep makes lots of minute tactical changes even in games which we don't notice. You can't just copy systems from coaches you have learnt from. You have to know how to apply it in real time in real life situations within an instant because you don't have the time to go home and think about how you'll go about it. Management includes lots of in-game quickfire tweaks which can determine the outcome. Pep, the coked up bald prick is an absolute tactical genius who is insanely rare in the industry.
And what I mentioned is just the tactical side of things. After this you have the man management, adaptability, creating an actual coherent philosophy, task delegation and many other aspects.
Playing/working under legendary managers means fuckall for your management career. Yes, learning from the best is always a positive experience but you have it in you naturally. Also it's always more beneficial to have worked under a Pep as an assistant (Arteta) than as a player(Xavi).
Now this comes to the point where you think of legendary managers who aren't necessarily tactical genius material themselves like Ferguson or Ancelotti, but these guys are insanely good at task delegation and man management. They know exactly the kind of assistants and personnel needed to help them. Carlos Quieroz oversaw the entire tactical training for Ferguson's famous United team.
Sometimes managers learn from a particular school of Football but end up developing their own ideas completely. Jose Mourinho learnt from the Barca school of coaching and went on the opposite side of the spectrum to Guardiola and Cruyff.
Xavi simply lacks anything resembling a philosophy. He hasn't learnt anything from Pep. Xavi has ZERO patterns of play. Just get the ball to Dembele who'll dribble and hit endless crosses to RL9. Zero penetration through the middle.
You can know a lot from the way managers break down tactics in interviews too. Watch Pep, Klopp, Tuchel, Mourinho, etc analyse any Football game and you go "Wow! Me or the pundits on TV never saw it that way".......I needed to watch one OGS interview to understand that he's a clueless PE teacher..