Kabuto-needed Oro's chakra in order to do it, summoned multiple Edos, could not control all of them at the same time (this is understandable), Itachi was brought back w/o Yata, Nagato was brought back slightly more mobile but still was quite crippled. Neither were at full power, in fact none of the Edos he brought back were close to full power. Maybe it had to do with how many he summoned?
Oro-Used his own chakra, did the research, completed the jutsu, brought back 4 hokages, could completely control the one who invented the jutsu, very close to full power, etc.
Tobirama-Invented it, but it was never completed to the extent Oro uses it. Has no feats with it.
Pretty sure Oro takes this. U_U