They would do better using the burrito method. It suspends the eggs up in the box and keeps them from hitting each other.I wrapped mine in bubble wrap individually and then put them in egg cartons and wrap the cartons in bubble wrap. Then fill the box with wadded paper. Works great, people had good hatches.
I have had a lot of egg shipped to me in California and the ones in egg cartons are always the most broken. That is my experience as both a shipper and an receiver of shipped eggs.
Chicken chick has a good article about packing like this. I know we don't like to change but give it a try sometime.