He also happens to be one of the most fastest players in the squad, Owen was small but was still one of the best headers of the ball going so height isn't all that (ala Crouch as well). Insua is a defender, it's his job to defend, and yes I'd much rather have Insua defending a corner over Torres, because at least if we hit the ball up Torres can chase the ball and we all move out and forward. As has been mentioned, the more players you have forward, the less the opposition are to commit into the box, so the risk is reduced somewhat.