The bolded is not really true anymore. It was previously, but it's exactly the tradition Overmars broke with a couple of years ago in a bid to achieve a stronger presence in Europe for Ajax. Hence Ajax signing people like Tadic and Blind.
I also feel like you're cherry picking a bit the last few pages to hold things against Ten Hag, to make it seem that he's responsible for what doesn't go well and less for what does. I might be wrong, but I don't think this is entirely deserved by Ten Hag.
This is still true. Martinez, Alvarez, Kudus, Daramy, Antony, Neres, Marin, Kristensen, Wober as some more. All young players that were bought. Sure Tadic and Blind were bought for the experience, but most signings are still very young players.
I'm not cherrypicking to hold things against Ten Hag. People are posting blatant lies about Ten Hag, he wasn't responsible for signing players, Overmars was. Ten Hag asked for a few specific players over the years and those he got. But those players usually don't work out(Klaiber, Labyad etc). The way it worked at Ajax was that the manager could ask for a type of player he needed for the squad and then Overmars & team would find a player. NOT Ten Hag, there is no reason for a DoF if the manager still makes the signings, sure Ten Hag was consulted. But the way it works at Ajax is the DoF makes the signings and the board even needs to agree about the players, to make sure it fits the clubs philosophy.
And some people are suggesting that i'm only negative about Ten Hag because he's leaving and that's utter bullshit. I haven't posted that much about him here in the past, but some of the posts here are consistent with i'm saying since he agreed to go to United. He's just a bit to reluctant to use youth players and can't really sub to change a game. But when his tactics work, they reaaaaaaaaaally work. So not that much to worry about for United fans. There were quite a few things that annoyed Ajax fans, because Ajax fans have extra demands for managers/players that usually don't apply to fans of other clubs. For example, most people think Haller is doing a good job at Ajax because he scores many goals, but for most Ajax fans he's just not good enough. Ajax fans(and me included) are a bit elitist