Don't know if this has been posted on here but there's a video from 2019 of Ruud Gullit and Erik ten Hag on Dutch TV arguing about how open Ajax's midfield is and how teams can just run through their midfield unopposed if they beat the press.
Interesting viewing as most of the clips used to make Gullit's point are from the Real Madrid Champions League games and the 4-4 draw with Bayern Munich in the group stages that season. Ten Hag defends some of the clips quite fairly IMO - one of the clips is them losing the ball during build-up, if you play out from the back in as aggressive a way as Ajax, you always risk getting countered if the opposition wins the ball back. Interesting to me that Ten Hag seems to concede that the midfield is being too aggressive (though there is an instance of him saying something along the lines of 'all the midfielders abandoning their position cannot happen and is unacceptable'), but that this is the risk of playing the type of entertaining football he wants the team to play.
But generally, I also think Gullit has a fair point about being a bit more conservative and having at least a few players back in midfield to protect the defence.
If I had to guess, I think the problem with Ten Hag is that he is a coach who has slightly negligent defensive principles and attacking principles that he adapts to his team/players/club. So at Ajax, he adapts the in possession style to the Ajax style. When he comes to United, he changes the in possession style to what he perceives to be the United way i.e., fast, direct, lots of play directed through the wings etc. But the problem is that at Ajax, since the build up was more methodical/patient, it masked the issues with his defensive principles because the defence could move up-field as the team moved the ball into the attacking third. This is still a risky proposition as you see in the clips above, but the defenders playing a high line at least allows them to step up and win the ball in midfield easier. Plus, in the Eredivisie, Ajax were so dominant that being so aggressive was not an issue as they could just pin teams back with their quality. At United, by being so direct (and Bruno and Casemiro are particularly guilty of this IMO, they try to put our attackers through basically every time they touch the ball), it has opened up a Pandora's box of defensive issues. And even smaller teams in the Premier League are too fast, too strong and have too many good players to not take advantage of the space in midfield.
But because these are his defensive principles in his ideal system, he's not really trying to alter it even though the same issues have persisted since the Wolves game on the opening day. He just reckons that with the right players, or with the current squad minus the injury issues, this system will work.
The people expecting a radically different approach defensively next season if we recruit well (get Amadou Onana and Todibo, say) or overcome our injury issues are probably going to be disappointed, I reckon. The question Ineos need to be asking is do they buy that argument that this system can work with different personnel or a fit squad that he can build 'automatisms' with (that has been his complaint with regards to the injuries, no? That we can't build automatisms because we have to keep chopping and changing). If not, then it probably is a better idea to just part ways this summer and get someone who's in possession and out of possession principles are more in line with what we think is likely to succeed in the Premier League. Even if we aren't sure whether the replacement is quite of the quality where we think he might be able to win the league for us (De Zerbi, Motta etc.), better to imprint the 'right' principles now, build the squad for them and wait for the next elite manager than keep going with a defensive system which we think cannot succeed in this league. If we think they cannot succeed, that is.
