Definitely the shipping is the main concern and not the breed. Personally I’ve found the bantam eggs to handle shipping better, with the LF eggs having more air cell issues and more early quitters or clears. No idea why that is, but that’s been my experience. The d’uccles I’ve hatched have all hatched well, usually over 50% hatch rate, I’ve had 100% hatch rate on red jungle fowl, and other smaller eggs. The ones I had the most trouble with were croad langshan and legbars, for whatever reason. Duck eggs seem to be the exception to my “rule” that I’ve been seeing - the bigger eggs are sturdier than the smaller eggs. It really depends on the handling, temp fluctuations, and pressures put on those eggs during shipping.