In that case, where we should try to get a wingback that could also play just as a wing is on the left. 'cause if we stat with 3 at the back, the one that can be used as a RB/LB is Chiellini, using him on the LB would left Bonucci and Barzagli as CB, with a RB spot yet to fill with Lichtsteiner. Asamoah can't play on the LB and I don't think he would be different on the LW. So, he should be the one we were trying to improve with someone who could work as a LWB and LW.
In the hypothetical case that we end up only with Sánchez and Llorente upfront, I'd be something like this:
Buffon
Barzagli-Bonucci-Chiellini
Lichtsteiner-Vidal-Pirlo-Marchisio-Asamoah
Sánchez-Llorente
then swicht on the fly to 4-3-3
Buffon
Lichtsteiner-Barzagli-Bonucci-Chiellini
Vidal-Pirlo-Marchisio
Sánchez-Llorente-Asamoah
See? It makes a whole lot more sense