Right, I will bother to do this now I'm at the computer and have a keyboard.
So I understand the approach of summer 2025, because there was pretty much no room for error. I do disagree fundamentally on splitting the work out in this way. The below sums it up quite well.
If I look at how someone like Arsenal did it, they didn't do it that way at all.
2021/22:
Ben White - RB/CB
Ramsdale - GK
Odegaard - AM/CM
Tomiyasu - RB/CB
Lokonga - CM
2022/23
Jesus - CF
Zinchenko - LB
Viera - AM
Trossard - LW/AM
Kiwior - CB
Jorginho - DM/CM
2023/24
Rice - DM
Havertz - AM/CF
Timber - RB/CB
Raya - GK
2024/25
Califiori - LB/CB
Merino - CM
2025/26
Zubimendi - DM
Eze - AM
Gyokeres - CF
Madueke - RW
Mosquera - CB
Norgaard - CM
Hincape - CB
There was always a smattering of loans, like Sterling and super cheap options to fill the squad up. Notice every window they bought a CB and nearly all of them could play FB as well. Not once did they opt for this big bang approach on one area of the pitch, because it's not a holistic approach and leaves obvious gaps. If you look at those players, none of them are or were 'best in class' or the biggest prospects (bar Rice, obviously), they are the right tactical fit for the style they wanted to play. The bolded would be those a big part of the title winning squad. Gabriel came in the 20/21 season and Saliba was bought and loaned out from 19/20.
So to me, progressing the team by investingin the profiles you want to implement your tactics/game model and slowly replacing the quality is the most important. We seem to doing a sort of field of dreams model, where if you build one bit as best as you possibly can, the rest of the team will follow - which I think is futile. You will likely run out of a) time b) money and c) fan patience with this approach.
You can build the great posession midfield, but it's useless when your team sits in and the spare men you have (FBs or CBs), can't contribute to the attack. If you also build an attack that are suited to transition football (I would say Cunha, Mbuemo and Sesko all are. Wolves, Brentford, any RB team), it's not really going to marry with a possesion heavy midfield. There needs to be more joined up thinking, else you end up with a frankenstein again, of good individual players, but not a good team or squad.
So in my opinion, we haven't done it the wrong way round, we've done it the wrong way. I hope to be proven wrong and will take that humble pie with pleasure.