For me, McGinn was poor for their second goal. Watch it again and see what he does. He is marking their AM on the edge of the box then, when that player plays the ball to his left, McGinn follows the ball - despite the intended recipient being marked closely - instead of standing still and staying with his man. The ball was returned to said man and he played it through to the wide man who crossed it for March to score.
If McGinn had stayed with his man he probably wouldn't have been able to play that ball through our defence.