It doesn't take much to disrupt us and to see us dragged all over the place, we don't hold shape when on the back foot and we don't pick players up in open play or, particularly from setpieces. As soon as that does start to happen, heads drop and mistakes creep in.
I agree that the players are part of the problem - Moreno has mistakes in him, but the biggest flaw is that when he makes a mistake, you know he'll make more, because his confidence evaporates. Same with Klavan, Karius, Lovren and Mignolet. That's more or less your defensive platform. Not a single one of them has a backbone in terms of rectifying their own mistakes through having the ability to calm the fuck down and to be intelligent about the play. And you can see it happening a bit with Gomez too.
Part of that is not having leaders and real class players in a couple of key positions to stand alongside them and to show leadership, either through just sheer quality, or good old fashioned intelligence and determination. But the organisational side of us is severely lacking. Our game, for the last several years now, seems completely and myopically focused on us always having the ball and being able to press. When that tails off, we haven't got a fucking clue.