Poch hasn't played 5-3-2 for ages and I still don't think he will touch it for a while with Lamela back and Moura signed too.
It's going to be ridiculous if we splurge £50m on Bale or whatever other attacking player only to play 3-5-2 and have only 2 attacking spots behind Kane up for grabs for 6 players.
If you want to play the odd game 3-5-2 you definitely still have the ability to do so with Sanchez, Dier, Verts and Foyth. Davies too can play LCB.
I'm really not too sure we need another CB, especially a mega money one.
Interesting how 3-5-2 seems to have had a one season moment in the sun. What worked for Chelsea now holding them back, Arsenal tried and given it up and we dropped it post Toby and our attacking play which was pretty turgid pre Xmas has looked much better to state the obvious although we've lost a bit of defensive solidity really only against Juve for those 5 mins and were overrun by City
So can see the logic in what you are saying - I would be more than happy to see Wanyama back in the centre and Dier spending more time in a back 3 on occasion - although Dier still makes mistakes at CB - more than Toby would anyway so as the two players stand today we do lose a bit quality wise in a Dier,Verts,Sanchez back 3 - against the top top sides if we actually want to win things still some risk with the back line