There are a lot of variables in shipping eggs. The packages get slammed and knocked around, many times damaging the eggs, despite the best attempts at packing.
I got two different bunches shipped to me this season. The first one appeared to be perfectly wrapped, no dents on the box. Not one chick hatched.
The second box was appropriately wrapped, the box looked like it had been around the world twice though! I put them in the incubator, figuring what the heck..... Out of 14 eggs I got 8 chicks, 5 hens and 3 roosters.
It is kind of like hoping for the best !