It's a bit strange that I've given you the option of Arteta in the middle (the Sneijder, Xavi or Ozil role), directing traffic and you want to replace him with Cahill! ha We could interchange other positions without much drama. Personally, I feel that switching flanks is an old trick used when wingers aren't getting much joy out of their fullbacks. If it was such a clever ploy you'd see Valencia popping up on the left for United and Malouda on the right for Chelsea. The system would be fluid enough to accommodate it though.
Barca play that way near enough every game. As they say, formations are neutral. It's tactics that are either attacking or defensive. If we were playing a team at Goodison who parked the bus, Coleman and Baines could effectively play as wingers, without worrying about leaving us exposed. We'd then stretch the opposition, leaving Osman, Arteta and Cahill to exploit the gaps.
Holland have Robben, Germany have Podolski and Barca have Messi. We'd probably have to sacrifice Ossie to include a winger. We could switch Cahill to the right and have someone like N'Zogbia on the left.