Last season Mandžukič, our backup CF, had 11+8 while playing out of position. Cuadrado, the very definition of a winger, had 3+10. I wouldn't say that Mario isn't useful attacking, he still creates and scores wherever he plays, just in a different style than you'd expect from a classic winger, I don't get why so many people have a problem with how he does it. We don't have enough grinta with Mandžukič on the field, if we take him off we turn into a fairy team with Chiellini looking like a crazy gorilla next to the others.
Besides, this season we have Matuidi in the center, who seems capable of breaking up play and bursting forward with the ball, which gives us another option