I seem to have a very different mental picture of this mural to the thatn the rest of you so I drew a couple pictures. First here's the desccription.
You seem to be imagining Mural 1. 4 pieces broken into 4 more smaller pieces representing the 16 shards and confirming the 4 divisons of shards theory. I don't think that can be right because the quote reads "4 of them" are further broken down. This would imply there are more pieces of Ado then the 16 shards.
I think it looks like Mural 2. 16 rays for 16 shards 4 shaterred for devotion, dominion, ambition, and honor.
What do you guys think, and pardon my ms paint.