Truth be told, in terms of songs, I honestly don't think much of individual parts there. You may well be right about that (and I even agree looking at it a bit closer). However, as I said, the album is more about its emotional voltage throughout whatever songs it has rather than having good individual pieces all the way. That's how it's bigger than the sum of its parts, since it -should- be smaller than it actually is objectively.
Mumford and Sons - Little Lion Man
This is one of the good individual pieces, though.
EDIT: I also have to note that Lost In Space is also bigger than Sigh No More in how it actually has no songs that are individually poor, and they all build a very cohesive whole to the work. But then, Aimee Mann and elegance.