But that doesn't invalidate him against your previous requirement to beat
any chuunin. Of course there will always be someone who's not someone's match, but your conditions didn't state that the Uchiha should be a demigod that wont be defeated under any condition (that would be silly).
Itachi was known for his Kunai skills as well at a very young age, plus he's considered as one (I can't remember if he's
the one) with the fastest hand seals, so he can use Katon Jutsu. Thow in analytically skills and calm composure, Itachi is not useless without his Sharingan. Gates is not a typical Chuunin skill, please.
I'd go with Madara, Itachi, and Hebi Sasuke at most.
