Both teams, Chelsea and Manchester United had bad performances and both teams could get good results even though both are about to get their coaches fired from the team. While we know Chelsea has a much better situation but in Chelsea they paid much more attention to the younger players and one good thing after Pochettino joined Chelsea is he had good changes in Chelsea and he let the older players go. So maybe we can't blame Pochettino too much like the other coach Ten Hag, because of Pochettino using younger players.
For the case of Chelsea, I am blaming the management for making some certain errors while signing all their players, they followed hype to sign most of their players and not given consideration to the Manager’s opinion and they changed managers like twice since the new ownership. These should affect the team’s performance because the management is yet to give any manager enough time to settle down and bring the best for the team; I think Pochettihnho will do better if given more years to settle down.
Manchester United on the other hand has given Ten Hag all the chances he deserves to bring back glory to Old Trafford but he failed despite all the time and money given to him to sign more players of his choice; I don’t think Ten Hag can bring glory back to United because it seems like the players are also tired with hims management because he tactics are not given them good results.