That could be true, but we'd be in a great disadvantage against tall, powerful strikers if we didnt have a tall centre back. Imagine if we played against Re Dtar, who have Nikola Žigić who is 202 centimeters tall, there is no way Canna or Gonzalo would be able to mark him.
It is a long shot, but I dont think we could guard taller players with a Gonzalo - Canna pairing.