You cannot assume the bits and pieces would be as un-aerodynamic as a penny. The flechettes dropped during WWI were deadly, but impossible to aim reliably. To make up for the inability to aim, they would drop hundreds of them at a time, covering large areas. Planes during WWI flew less than half the height of the Chinese balloon.
It's irresponsible to claim that it would be safe to shoot down something like this balloon over land. I don't understand why you're trying. You surely know better. If you can convince people that it would be safe, are you sure that would that advance your tribal position?