He awakened the Rinnegan shortly before dying, and he at least knew Nagato before dying, making him pretty damn old. So Rinnegan Madara would be an old geezer if using him in vs threads.
Doesn't Edo Tensei awake you in in the state you were before death? Or did Kabuto take Nagatos DNA after his death, although Konan took his body?
Madara is not overrated. Firstly the Edo Tensei does
not grant you unlimited Chakra and secondly Madara isn't reliant to his regeneration, he was damaged by the Kages several times but yet he played only with them; Oonokis first hit with the Jinton Madara didn't absorb purposely, in order to show them Hashiramas face.
If Madara would go at full, using the full power of his EMS, Rinnegan and the Mokuton, no one would actually scratch him.