I’ve said a few times that I’m not a fan of these ‘system’ managers. More often than not they either A: Work for a bit then get worked out or B: Only work in very specific circumstances and club profiles.
I think it’s fine for managers to have a preferred style like Ferguson, or Guardiola - as long as they do evolve their systems to stop it being predictable. On the other hand you have the likes of Ancelotti who’s very pragmatic and gets results.
Broadly my feeling is even if they want to build to a specific system, then they do need to be pragmatic to a degree and actually win games - and just whining about not having the players to play their system or blindly playing it getting loss after loss is being a bad manager to me