I thought that the edo tensei resurrected the dead not revived them and gave them a makeover. In the latest manga they show madara in a close to death state. and when he is resurrected he looks like new.
when madara was brought back i believe that kabuto
said he was brought back better than at his
prime...and at his best (probably when he fought
harashima) he didn't have the rinnegan, yet
the edo version has it, so the Madara in the 4th
war is a better, altered version of the original