Of course you wouldn't scream "I'm the sage" in public. Don't pretend that's what anyone is saying. No PMs means you have to be smart about what you say, and how to interpret what other people are saying.
I would be interested in seeing the complete PM exchane for the Sage for the Masahakon game. I bet the majority of it is not trying to convince people who you are, and that you're genuinely the sage. I bet most of it is working together to figure out who the enemy is. IMO, that's only playing half the game.