How would you measure relational equality?
How would you measure the balance of power between states? People don't really bother to, because it isn't necessary to. What matters in the end is: Do women as a class have sufficient means at their disposal to keep the threat of exploitation at bay without having to depend on the goodwill of men?
Also, "equality of outcome/opportunity" is a nonsensical distinction. If it is true that we live in a deterministic universe, then equal opportunity must necessarily lead to equal outcome. If not, then there are unequal differences from the very beginning, whether environmental, biological, or both, that can potentially be corrected through social policy or medicine.