Carlos was extremely overrated. He was in Inter at one point iirc and Serie A proved to be more difficult than he had expected. As for his defending I'm not sure if serious, but he never stroke me as a defensively sound player and Zambrotta was miles ahead. Another thing; every time Carlos went against those type of players, as I remember games vs Bayern and Salihamidzic, Juve and Zambrotta, he would be completely out of the game. Not that great even offensively when he faced defensively and tactically sound players.