definition of "whole loaf" for lechem mishne

To properly fulfill the requirement of lechem mishne on Shabbos requires two whole loaves, but a glance at your typical challah roll smushed into the bag among others will inevitably reveal flaking crust, bits of dough hanging over from where it was broken away from its neighbor, etc. How whole does whole have to be? As far as I know you won’t find a standard in hilchos lechem mishne, but you do find a standard in hilchos eiruvin. The gemara (eiruvin 81) says that an eiruv can be made with a whole loaf but not a partial loaf, even if the piece is greater than the whole. The reason for the din is eivah, to avoid an argument between parties over why one person only gave only a piece and the other gave a whole loaf. The gemara says that the shiur challah (for a baker: 1/48) can be removed from a loaf and it is still considered whole. Tosfos assumes that this is only true id the shiur challah actually needs to be removed for the purpose of mitzvas challah, otherwise, the parties may still fight over who gave a whole vs. who gave a part, but the Rosh argues and assumes that the reason why a small part is missing is irrelevant. Once people are willing to make a concession and allow a small part to be missing for the sake of challah, whether that small part was actually taken for challah or just happens to be missing is not important. The Korban Nesanel interestingly writes that this is true only with respect to eiruv where the criteria for wholeness is dependent on people’s tolerance (the purpose of the din was to avoid argument), but not with respect to lechem mishne. However, the Shmiras Shabbos k’Hilchisa in a footnote writes that R’ Shlomo Zalman disagreed and assumed that the same standard applies in both cases.