I don't think the bread&butter comps are as dominant as people make them out to be. Yes Noble6 and Draven are really strong, but I've won games with Void Assassins, Pirate+Gunslinger/Blademaster and Yordle6 (before Lulu bug) against full-build teams. I've also seen lots of Sorcerer and full glacial builds do well but I hardly build them.
Positioning is very important.. far more than people are giving it credit for at the moment.
For instance, when I was running pirate blademaster I was really struggling (last place) until I reshuffled my team, made a straight line at the front of my board with all my melee units.. then went unbeaten until I won the game like 15 rounds later.
Same with my assassin comp. I noticed they wern't able to dive on the 3 star Sorcerers that the #1 person had, so I pulled all my team away as far as I could (even frontline to the edge of my own board) so the enemies tanks had to move forward a few squares each round.. it left enough room for my assassins to jump in and actually oneshot the sorcerers before swapping targets to the tanks.