I think the concept of "equal footing" is an artifical product that probably has no validity when real emotions are involved. To seek it out seems to be more like looking for someone to fulfill a contract between three people. Triads are viable and I know of one in particular that is thriving after much struggle and finding a workable balance. Even in that case there is an aknowledged difference between primary and secondary relationships (for lack of a better word). There is no illusions about everything being equal it seems. They are all in love however and so they continue on without any notion that everything will be equal.
Playing the Game of Life with Monopoly rules.
Monogamy might just be in my genes
Poly Events All Over