Come off of it all of those guys spent most of their careers at CB and had the quickness, aerial ability and strength to make up for their lack of height. This is probably a non issue since Blind is probably just a placeholder until Rojo is fit to play and with Jones suffering from illness it is not like we have any other options. But, it is silly to just ignore that Blind just does not look like a suitable CB. He has none of the important physical qualities you would look for in a CB. Really find me a top CB who isn't quick, who isn't strong and is not effective in the air? Most top CBs have at least two of those qualities. Best case Blind can be as good of a CB as Carrick or Busquets.