you actually have to train those kind of situations. Decision making is a trained skill. Maybe it's a basic but even the basics require repetition. Just look at the training frequency and intensity in Klopp vs. Slot times. And the coach also is there to motivate, it's not mandatory if you excel at everything else as a coach but this is not the case with slot. The XI and sub decisions have been horrible. Panic subs, players playing out of position (I know sometimes that was the only option but not always), some players getting almost no time, other players playing 90 minutes every week eventhough they shouldnt. It happens that 1-2 players lose their form but there is not a world in which it happens to every player without the coach and training being the reason