I would put all the blame on Ten Hag because he is the only coach that has used a huge amount of money to buy players above their value which is affecting the club performance and financial state. All most all the players he bought are all average players who cannot withstand the pressure in the EPL competition. United bought the wrong players and expected a magic or what.
Ten Hag really made very big changes at Manchester United. His strategy was clear, he was doing the same thing he did at Ajax, buying young players and believing he could turn them into a strong team. In fact, when he was the manager of Manchester United, the team’s results were much better, and when he left, everything fell apart. You are right that the transfers he made did not deliver the expected results and the management did not want to wait any longer. And now I doubt that Amorim will be given the same transfer budget.
We can say that the entire budget was spent during the Ten Hag period at Manchester United. The Dutch manager made transfers as if he was playing Football Manager and expected efficiency from the players. However, football is not exactly like that. Now, the Manchester United management has to adjust the budget for the Portuguese manager who was brought in to get rid of this difficult situation he left behind. It will be very difficult to adjust this budget because the value of the players bought during the Dutch manager's time has decreased. When they want to sell, they will sell at a loss. This will cause them to buy good players at high prices.