Then that just goes to show Del Neri is a shit manager.
You form the system around the players you have at your disposal. It's as simple as that. If you have several great wingers on your squad, you don't go ahead and use a system without wingers.
I mean come on, to explain this concept is like teaching a high school student how to add and subtract.
Unfortunately for us, though, that's the sort of management we have, high schoolers and fucking retards.