The reanimated Nagato used the Six Paths Techniques while fighting Naruto and Killerbee. When Madara was reanimated, he thought he had been revived by Nagato as planned. Can Kabuto or Tobi not make Nagato use the Rinnegan's Outer Path to revive someone, such as Madara, so that they would not need to use the Edo Tensei on him?
Please disregard the fact that Kabuto wanted to control Madara, so he had to reanimated him using Edo Tensei.