nice theorys and efforts for your work,but i dont think oro has something to do with madara/obito plans,the only thang that oro wants is power , i guess he try to get sasuke's body somehow cuz it would to hard for him to get madaras or obitos body somehow cuz they stomp him in quite few secs down. + rep
Why are you sure that Madara knew the edo tensei from orochimaru? Madara knew Tobirama as well...and he knew about the original purpose of the jutsu so I'd say that Madara referred to Tobirama ,not Oro. And maybe kabuto was referring to Tobi because at that time Kabuto was supporting Tobi in the war. But yes, Madara might have had a connection to Oro and its very possible as well that both of them wanted to recreate the so6p's powers.
To respond both of you about Madara knowing Oro or the otherway around.
Who was the first one to have Hashirama's DNA? Madara...
Who was the one that conducted tests with Hashirama's DNA? Orochimaru.
Who could be the only one who could've give the DNA to Orochimaru? Madara.
It's simple.
I already explained... Madara knew Tobirama as well, but in order to keep his death fake he didn't have to unveil himself to Tobirama or else the news concerning his death would've been exposed.
I frankly doubt that Tobirama would just shut up in regards to such a secret.
So that's why I think at a certain time Madara and Orochimaru met, they traded Hashi's DNA. Don't forget also that Orochimaru was a member of Akatsuki as well and supposedly (we still don't know exactly) Akatsuki was created by Madara.
The other things were assumptions but I am pretty sure that Madara and Orochimaru know themselves. They could have met around the way as Orochimaru was old enough to still be able to catch alive Madara.