Dier is a good player, he's proven to be such, not great but good, highly versatile player that played at the heart of our midfield in the best team we've had in two generations. Toby was one of the League's best CB's for a short period but has reached that time in his career where he is starting to really struggle in an increasing number of games (quite why he went all out to sign him to a massive new deal is a major miss judgement).
I don't blame him for thinking that he could do better than Poch, the ego's and belief most managers need will be seen from anyone else taking the role eg I'm sure Nagglesmann would have the confidence in his own ability to improve on Jose.
But, mangers like Poch or Nagglesmann know that their coaching requires the team to play a system, I think their belief they have is how they get a team to play a certain way, get them to believe in this way. Jose's approach appears to have his players to believe in him (not the system because there isn't one).
Dier was good - but he's far too bulky now
Alderweireld just got old
Agree he has no system....its monopoly football, roll the dice and see what you land on