i'd say i consider messi/pedro/villa attackers.
how can you all say it would never work if we had something like
vucinic/matri/jovetic
the pressure alone for holding that attack power would keep their fullbacks in defence,hence not needing more player do defend.
so if you replace pepe with ,lets say, jovetic.even though he might not defend that much, he would for sure make the other team's left back stay and keep a close eye on him rather than attack for fun like everyone is doing with pepe.