It's not. Madara is in charge of Akatsuki. But only Pein, Itachi, and a few other members know who he really is. To protect his secret, his orders come from Pein and Zetsu.Originally Posted by animus
If there's any possibility of it being stronger, it's because it works as a P2P doujoutsu.
Still, I don't expect Jiraiya (our source of information on the Rinnegan) knew very much about the MS, considering he had never seen Itachi's black flames before his brief fight with Itachi and Kisame.