Well, how did we do it last year? I think it's definitely weird to have multi heroes in single brigades (Daniel in white, lolwut). What we COULD do, since multi heroes are generally stronger anyway, is have the winner of multi face the winner of the rest for the last round, or something like that.
P.S. Totally didn't know that "cat" was an abbreviation at first look, and could only think of Nyan Cat farting rainbows.