Mangala didn't come out of that well but if we'd set up like Swansea, with the back line on the edge of the area and the 3 midfield players about 15 yards in front, then Gomis just doesn't get that space in the first place.
And if we set up like Swansea, maybe we would score the same number of goals that they do?
And saying "Mangala didn't come of that well" is the mother of all understatements. You can't blame the defensive formation for plain bad defending.