Chelsea have since struggled to adapt with the huge changes to personnel and pochettino has not been able to galvanize the squad that was already on a freefall having work under Thomas tuchel, Graham potter and frank Lampard last season and also with the sweeping changes on the front of transfer I think Chelsea are still coming to terms with pochettinos method which notoriously demanding and require high fitness
Of the 3 coaches you mentioned, I don't see any real change for the better. Even when they spend a lot of money to bring in a number of players, the change is not visible. This is an internal problem in my opinion, and the most likely to mention is how the coach cannot give instructions properly according to the player's ability, or the player who cannot carry out the instructions given by the coach properly. For now they don't need to think about whether they have to win the match or not, because the most important thing now is that they have to improve their weaknesses, because if they are better then the victory will follow.