The heavier pieces travelling further would though, be more likely to sink, no?
Thuis reducing the apparent surface debris field?
As the piece separated fall from a higher height, they are more affected by the air on their shape. This means they will land further away from each other, you would expect wings, back fuselage, forward to all end up in different areas and some to stay off to the side. Pieces would also come down with high air resistance on them to their weight, which would hold together more than a piece being aimed with low resistance and high kinetic force.