We had some really bad games with ETH playing that set up though?
Of course we did. Thats why he was eventually sacked. Formations aren't the root of all evil but some formations are more adaptable and some suit different leagues more than others. Crystal Palace are playing 5 at the back as well. The difference is that they are doing a better job of it and playing on the break and they have a good midfield 2.
For Amorims formation we need better/different CMs, potentially another CB, definitely a better LWB and even then I don't trust that this formation works that well in the PL for teams that are looking to dominate games. Thats another £250m to gamble on adapting our team for Amorim who hasn't shown very much at all in the way of being able to handle the job. Thats £250m more to move away from a more traditional system and buy specialist players and push out some of our best current players.
Bruno and Mainoo have no place in this team by the looks of it.
I just don't see how keeping him and leaning into his plan has a good chance of paying off and there is a huge risk of being in the middle of a rebuild again in a year or two when hes replaced and we are limited to manager who play 5 at the back or again, spending a bunch of money to go back to a more traditional formation.

. Should have Cunha back and maybe Sesko - although not 100% convinced he makes that big a difference unless Dalot and Dorgu learn how to cross the ball in the next fortnight.