Reassembly of original constituents serves two explanatory purposes. First, bodily resurrection remains genuinely bodily: it is the same individual restored with a body. Second, the entire account need not rest on the disputed premise that something utterly nonexistent can return numerically unchanged.
For a limited analogy, imagine a structure dismantled into stones and subsequently reassembled. That makes the distinction between dispersal and complete annihilation intelligible. The analogy has limits: human life, consciousness, soul, and personal continuity are not equivalent to an inanimate building. It illustrates only the logical possibility of reorganization.