Third Heavy Weight

In the schweser mocks, they always have 4 vignettes for equity and FRA each. I have also noticed 2 for Ethics and 2 for Derivates, and corp finance, portfolio management, and fixed income vary in the sections. I have seen people talking about third heavy weight? I would like to hit the third heavy weight real hard so even if I don’t score in the other light weight areas, the third one covers up. I definitely don’t want to rely on Ethics.