When you build the team seems like is fine, but after a few looks, you start to realize is better to have some 4.5m defenders and taht 1.5m remaining can do a much better work in other parts of the field.
You can look at it in many ways. There will always be midfielders and attackers that will get you points but I am thinking Arsenal is probably hands down the team that will keep most clean sheets this season. Yeah they are expansive but well worth the price.
I will always advocate mixed approach, have all price points in every part of the field. Meaning at least one premium player in each part of the pitch, for instance Haaland, Saka, Trent; then at least one mid priced option like Jackson, Dias, Porro and then one cheap player but with good minutes and fixtures like Wood, Semenyo, Aina. By the way all those mentioned players bar Jackson will be on my WC if I decide to play it this week.
In addition to that leave 0.5M in the bank and you have an easy way to any player in the game with just one transfer (except for Salah but you can't have everything).