Defense is not dependent on defenders at all, it's a team effort. How did Juve get their defense right with Defenders like Chiellini and Bonucci? By having mids who would press the fuck out of the other team.
Rami-Alex-ZAPATA is a good decent CB trio. DeS is a good Side back, the rest is pretty meh.
Constant put on a really good performance two year ago against Barca. Reason? He was covered by mids, so he had to deal with one player at the time, which he was able to handle. If you have 6 guys running at you full speed and you're all alone then definitely you gonna slip. It's not a mistake, it's team playing bad defense.
Our midfield and wingers need to put pressure on as soon as they lose the ball. That's one of the reasons why SES is so important. It's not a coincidence that when he played Constant did a better job. He tracks back and he defends.
We need to defend as a unit, like teams like Roma or Atletico. Defenders are merely specialists protecting the box, just like Strikers. We have a really good CF in Mario but that doesn't mean our Attack is good, because it's a team effort. Every guy must play their role in both defense and attack otherwise it's gonna fail.
Why did Barca's defense turn to shit? Because they stopped pressing. It had nothing to do with defenders. Pique was not that good of a defender before he supposedly "declined". He had less to do before because guys in mid and wingers would press madly. They stopped doing that, their defense opened up.
Ramos was a beast in Madrid, a clown in Spain. Reason? The whole team didn't play defense, they would go in other team's half, and they would be countered easily since nobody wasting putting pressure on opponent immediately after they lost possession the way they did before.
I don't think anyone had Godin as a top 10 defender in the world last year, but he was the centerpiece in one of the best defensive teams.
Rami, Alex and Zapata are no Nesta, but if we fail to defend decently it's not gonna be because of these guys.