The Rock/Paper/Scissors design kept stances from being very interesting. It's always clear what to do when your opponent has a stance that dominates your stance, no thought or judgement is necessary. I'd like to see stances matter, and see two ways not mentioned previously.
First, add to the original design: instead of Rock/Paper/Scissors, make it the
Rock/ Paper/ Scissors/ Spock/ Lizard design (
wikipedia).
There are ten possible pairings of the five gestures, where each gesture beats two of the other gestures and is beaten by the remaining two. The enemy's response to your stance is not obvious, and neither is your response to the enemy's stance.
The other change is to make the stances provide benefit against certain kinds of attacks:
Red: +resist/+ward to all Mystic spells,
Blue: +resist/+ward to all Arcane spells,
Green: +resist/+ward to Pierce/Crush/Slashing
I prefer the 5-stance solution over most of the other proposals.