For the sake of schools getting to overpowered in a certain area, I think its time our wizards started learning an ACTUAL secondary school. We should also have cool gear to support every single school combination, or let us wizards customize which school stats we want to use on our gear.
What if someone made their secondary school their primary school? I think it should make their weaknesses even MORE prevalent, and their strengths persistent and stable. So for Ice, they start to get innate negative damage per level, but also innate resistance. Or for storm, they get innate more pierce per level, but negative resistance.