[he smiles just a little, glad yet again to see that Croix has a head on his shoulders]

Well, that's just it. Some of the fragments did want to be whole again, and got it into their agents' minds that that's what they should do. But it's not possible to recombine something that's been shattered. It's like that children's nursery rhyme about the broken egg, or if you've ever broken a glass. Once it's shattered, you can't fix it so it's back to the exact condition it was in prior to breaking.