This seems fallacious to me. Energy scales linearly with mass, so an object that is twice as big, is twice as bad. It probably isn't even twice the area, unless

This seems fallacious to me. Energy scales linearly with mass, so an object that is twice as big, is twice as bad. It probably isn't even twice the area, unless it's a flat sheet hitting broadside on - but even if it were, that's still at best the same as getting hit twice. Or are you saying that gluing two small pieces of debris together render them less harmful?