1 minute ago, Diogo Salazar said:You don't need movement in mass combat. The rules say that you can reach any point of the battlefield in a given turn. It's not me being literal, it's me reading the book as presented.
So, these are the four basic actions for Mass Battle they all share the Movement keyword with the exception of Rally and they all require a check, so, again, Water Stance won't give you an extra action and won't give you extra movement. And nothing says I can't use Fire Stance to lead a really scary cavalry charge or even Void if I am willing to lead a cavalry charge against a wall of spears.
you are being too literal. You would use water approaches for charges, flexible tactics cavalry charges, the key words of the approaches are what matter.