team uchiha... one word experience and skills....
Nagato has more experience then Itachi, Madara has next to no experience dealing with the Rinningan.
Naruto's newly activated power and Nagato's experience with the Rinningan gives them a power advantage.
Skill wise, both Naruto and Nagato have what it takes to defeat Itachi individually so the only burden is Madara really, however the person fighting Itachi (more then likely Nagato) would be have a hard time defeating them but eventually I see Itachi being the first to be taken down, leaving the person he fought in critical but still useful and Naruto has match for Madara, as far as what has been seen.