Quality is better than Quantity, I doubt Tobirama went about like a snake obsessing over collecting dead people, but he was the inventor of this jutsu, and as such new of ways to utilize it to its full potential(without collecting a bunch a ninja), that infinite explosion jutsu he used on 10T jubito would have destroyed any other ninja i assure you, but because he is the 10T he is OP and thus still alive and kicking and shit. Kabuto has DSM and Edo, Oro has Edo, and probably will perfect it even further lol Kabuto is fodder, all he has to himself is DSM.