The only one of those linked to leaving is Darmian and he may end up staying if no one pays the price for him. Sanchez, Bailly and Rojo, I haven't seen anything lining them to leaving any soon. Who is going to pay Sanchez salary? And Rojo doesn't look interested in taking a paycut.They are. They're not all the deadwood though. Sanchez, Darmian, Bailly and Rojo could all still go.
Given Herrera, Fellaini and Valencia have already gone and Pogba, De Gea and Lukaku could go too we're potentially seeing a rapid turnover of players as is. Between all those potential sales we're already likely to see as many outgoing as the club could reasonably cope with.
Also losing good players as Herrera isn't called "casting off".
City got rid of their entire fullback set to buy new 3 fullbacks to solve the problem. If it were for people here they would have kept Zabaleta and Kolarov for "squad depth". That's the difference.