Madara cannot simultaneously fight two fellow [albeit inferior] Susano'o users, a top tier Sage Mode user, and a guy with a built in respawn feature (without taking Kotoamatsukami into account, mind you) while simultaneously avoiding Shikamaru holding him in place and dodging insta Kamui snipes from Kakashi.
I'd argue that Itachi, Sasuke, and Kakashi would be enough here given the fact Madara cannot spam his meteors due to the fact he has the ability to die in this match. With dual Susano'os the two brothers can keep Madara distracted long enough for Kakashi to warp him. Hell, with no knowledge, it is impossible for Madara to dodge Kakashi's Kamui.
