I'll repeat it again..Andrade covers for Amancio.
It's Hughes, you ought to know your own team better!
Good on the ball. No afraid to step out and defend if necessary. Very intelligent and understands space and knows how to shut down angles. Won't be beaten easily on the ground or in the air.
The first one is when he's on the ball, irrelevant when he's being attacked by Elkjaer.
Not afraid to step out - alright, sorta relevant but I'll club it with the next one:
Very Intelligent - sure, I buy that and that is great in cutting down the service or eliminating a danger before it arises. It helps, sure.
Won't be beaten on the ground or the air - is that your opinion or any basis to that? How strong was he to battle against someone like Elkjaer who possesses extremely strong hold up play?
Now let's consider what you didn't address:
Number 1 - Pace. Is Blind fast? Faster than most CBs? Faster than Elkjaer? That is an incredibly important metric in this context to guard against the countless counters I will throw at you.
Number 2 - Alertness and Awareness. You can call it reactions. Was he quick to react? Slow to react? Again an extremely important metric.
Number 3 - Strength, both aerial and physical. Again, how does that fare against Elkjaer's?
Those are the obvious question marks.
Now, one of my most obvious route to goal is carrying the ball down the right flanks with Amancio and Sagnol with the others breaking through the middle and the left. As per your own admission, you will have Hughes and Nadal against Amancio and Sagnol, with Stiles running along or behind Cubillas and Andrade guarding the trademark darting runs El Matador makes into the box.
So in this scenario, who else is there to cover Elkjaer apart from Blind? It's a (terrible) 1v1 for you. More so because it's not an traditional aerial striker who will simply try to win a header, here's an extremely clever, tireless and cunning all round centre forward who will exploit the situation whether it means scoring himself or letting it go for a better pass in someone's path.
Is that not a quality scoring route?
1. There is no one covering behind Blind if he gets beaten by Elkjaer be it through pace or strength.
2. There's no one to man the space that will be exploited by the likes of Cubillas and Kempes making late runs into the box. Both their markers will have to track them each and every time they run into the box, it's virtually impossible and never seen in a football game.
3. It's a perennial 3v3 or rather 5v5 at the back for you, nevermind that all that's at blistering pace and not giving any time for your backline to settle into shape.
Your defenders will have to constantly make fatal calls on which player guard when all four are on the counter and it would be pretty easy to pick the unmarked one out. Not to mention you are hoping them to play the perfect offside line, which isn't going to be easy given Blind is instructed to step out constantly and would generally be dragged away from his position by Elkjaer. In a scenario like that he can easily play in one of Kempes or Cubillas who can evade their markers and attack a space their markers are not instructed to guard (you have admitted that there is no man marking which means they won't follow them all around. e.g if Cubillas drops to the left Stiles will leave him for Andrade, etc). All I am trying to explain is the basic fatality of your defensive strategy. In all of this I have not yet included the amazing all round qualities my attacking players possess, it's simply a numbers problem, you cannot overcome. You cannot also overcome the problem posed by constant movement, interchange and link up at pace by fielding that highly risky backline.