The juubi is dead which is the main thing he needs for his big plan , yet we dont see him doing anything, but sitting down and waiting for the real hashirama to come out.
madara is sitting in d corner like a gud child and waiting fr his real crush to fight him.... kishi has really made a laughing stock out of madara ... XD
That probably wouldn't even damage the Juubi much, if it did at all. Madara is simply confident that they wouldn't be able to damage the Juubi and is waiting for the final transformation.