Juggernauts are balanced. 100% Fact
However, as someone who plays Twisted Treeline frequently they are a problem. As well as some others. Darius when rate is over 60% because his kit works TOO well on this map. Riot, remember when singed was a huge problem, high winrate on TT? What did you guys do? You tweaked him back some. And it was fair and just.
All I'm saying is, certain champs on TT really need some of their numbers dialed back JUST FOR THAT MAP.
EDIT: http://www.lolking.net/charts?region=all&type=champion-winrate&range=daily&map=tt&queue=normal
Heres the actual numbers for why they are a problem on 3's. 60% winrate?