The best defensive side since last December is a big, big exaggeration tbh...
Listen, Blind is not a centre-back. If we want to compete and win things, we need top quality players playing in their best positions. Blind is neither.
What happens when we face top opposition? Blind will probably be targeted and quite honestly, I don't see him coping with top attacking talent. In defence you need players who can defend first and foremost... Blind isn't that at this stage. Look at Mascherano - he only works as a defender because he's by nature one of the, if not the, best DMs in recent years - great positioning/awareness, great tackling, great speed.
About the distribution, I don't know what you're getting at, I've watched Otamendi live twice recently and he was vital for Valencia in the passing department. Actually, he was their only defender who had the ability to link defence and midfield effortlessly.
Quite honestly, I'm not convinced by Van Gaal's "philosophy" or "process" when it involves players playing out of position and not to their strengths. Players getting instructions not to try anything with the ball, not to try through balls if there's a chance... At the start of last season, only Di Maria having some freedom to try things, this season it's gonna be Memphis. Honestly, that's just bollocks - you can't play attacking football without taking risks... And we all thought Van Gaal was all about an attacking style football, 4-3-3, etc. With him in charge, we seem to be afraid of not having the ball - why is that, if he believes so much in Blind at CB?