Because Ashworth said once that he won't force a player on his head coach, normally you would expect a competent DoF to be able to convince a head coach that player X is good, otherwise they will have problems, a proper football structure led by a competent DoF has the job of bringing in good players into the team, Ten Hag for example said De Ligt & Maz were suggested to him, rather than him asking for them, and he shouldn't ask for players, the head coach should focus on the team as is and make it work, the DoF and the recruitment team will work on identifying gabs in the playing squad and filling those gabs with the right players