Faze had a good honeymoon period, but once that was over they were behind sk, and then behind astralis, and now they are behind liquid, astralis, and navi. Their dominance came from their strong individual performances plus the fact that there were not other strong teams at the time, until SK and Astralis changed players. Now they are even behind nothing special teams.
Fluke, I do not see how it was a fluke. They were the best team at the major, so they won, just like c9 did. Karrigan has never made his team close to the best team in a major.
Using their whole careers is pointless, comparing Gla1ve in Astralis to Karrigan in Faze makes sense.
Looking at purely IGL ability and not their player abilities I would put several IGLS above karrigan.
Fallen, Glaive, Zeus, TOAO, Nitro, ChrisJ, xSeven. Thats just after a quick look.