I won't call all signings that aren't living up to expectations as made for Ten Hag. I was merely referring to the decision - was it just because the manager can work with them or was it because the club actually needed them? For example: to me Malacia wasn't a signing tailored for only Ten Hag because the club desperately needed a left back and any manager could have used him. Shaw was always injured and Malacia a good young talent to have as a backup (until he himself got injured, unfortunately but that is outside of club's control). Did Ten Hag want Malacia? most likely yes, he knew the player inside out, but he's a player the club could use regardless of manager. Maz has found himself in a similar position, even if he wasn't this good, I'd still call him a good signing because the club needed him.
De Ligt and Zirkzee seemed to me like the players Ten Hag knew about and could use, so we went ahead and sign them. Did the club actually need them? I don't know - we had so many CBs already and we surely needed a more experienced striker than Hojlund, not another potential. And to make it more confusing, it turns out Zirkzee is more like a 10 but we have Bruno, Mount, Eriksen, Amad, and to a certain extent Mainoo in that position. And what's even more confusing is someone agreed to spend decent money on them knowing the manager had a big question mark as whether he'd continue after the season or gets sacked in the middle of it. As for the reports, the mirror doesn't strike me as a very reliable source. I'm not trying to blame Ten Hag but it's hard to imagine him not having a say on dutch talents as he has an extensive knowledge about them and the connection. And to be fair, Ten Hag had a history of filling in a position with a player, that looked like only him can make it work, namely Weghorst as a defensive striker.
That's why I like Amorim. His system allows the club to replace players easier. Because their role is clear in relation to the system. None of these "striker but defensive and hard working, no goal", "winger but can't beat his man but has good work rate". Seems very hard to replicate by other people.