Rather than learning the techniques of the Water God Style, for a North God Stylist it would probably be a better countermeasure to simply hone their own techniques. After all, unlike the Water God Style that couldn't be learned properly without a fitting opponent, the Sword God Style was a style that focused on taking the initiative and speedily grasping victory, regardless of the opponent.
To gain experience in fighting the Water God Style specifically suggests that he plans at some point to have her fight someone of the Water God Style, thought Reyda. And there was only one Water God Stylist who the Sword God didn't think could be won against without going to such lengths.