one thing i've noticed with de ceglie, isla, lichtsteiner, and asamoah, none of them ever look up before they cross, its just blind crosses all the time which is why 8/10 times it rarely even beats the first man, that has been my main criticism about this system.
if you played football in any league but the very lowest, you would know that there are hardly any situations where you cross for a player that stands still in the penalty box. crosses like this are way to easy to defend. the only situation where you cross for someone specific is when you have numerical advantage and try to connect with a player who is unmarked.
in crowded penalty areas as those we play against you need to play the ball with enough force into space between defender and goal for a striker to run into and score, that's why the movement of the striker is essential. vucinic can't do that. quagliarella can make those runs but only very limited. the situation where lichtsteiner crossed and quags nearly scored was symptomatic for the crosses you want. it went in behind the defenders and all it takes for the striker is to anticipate the cross a bit earlier than the defender and he has a very easy chance to score.
the fact that our wing players don't look up before crossing is also as already pointed out due to their difficulty even going past their man, so when they are finally in a position to cross they used so much of their energy to get past that one player that the accuraccy and time for a good cross onto a target are not available anymore.