I don't intend for this to sound rude but I'm not sure if I can believe that and if it's true thats a terrifying thought.
If your answer to fixing the shortfalls of the players you've picked in your system is to switch to a flat 4 then why are you playing that system to begin with and secondly the system you're switching to is even more unsuitable - Lallana ends up as a cm with Rooney and Wilshere ending up wide?
I'll ask at my meeting tonight, will be interesting to hear, guarantee he'll say the same thing as me. it's dependant on the other players on the pitch. You do seem to find it hard to get your head round how players move on the pitch, you seem to think a player stays in one place and doesn't move. Where a formation is a rough guide as to where players occupy space in offensive and defensive formations. It's not an absolute, certainly not as this level where players are intelligent enough to occupy a space which has been left open due to whatever reason.
It's really not hard to get your head around a defensive setup in a diamond which i'm suggesting be 4-3-1-2
-----------GK-----------
RB---CB-------CB-----LB
-----RCM--DM---LCM
------------AM
--------ST------ST
Again, you seem to think the formation is unconditional and that there is no evolution within the game, if the opposition is finding space down the right and doing well there, you bring a striker out right to help the situation. You can tell Wilshere to budge out a bit with Lallana dropping in, there's many things you can do but you can't seem to get your head round the leeway in a formation, it's a guide for players which then evolves as the game goes on.
We have very good strikers in the England setup, not many good wingers, lets make the most of them. Which ever central players you want to use, you can, they are top level players, they aren't going to be clueless as to how to play these positions. Milner/Wilshere, Ali/Rooney/Lallana, which ever combo you use really.