People keep saying that, but clearly Edo Tensai doesn't require the physical body of the deceased, but rather clones the state of what it used to be prior to the person's death. Orochimaru was able to resurrect the 1st hokage, despite him being in Madara's possession all this time. Nagato would be missing a rinnegan. Hizashi would be blind right now since his curse seal destroyed his byakugan eyes. Deidara would still be a million pieces strewn across the land. Sasori would just be a flesh cylinder, etc.