I personally would series-connect the main leads and replace the two balance taps with a single 6 balance connector of your choosing. Then, it's just a matter of wiring (and one balance wire won't be used; like in the diagrams on my calc site).
I would assume that one of the black wires won't be used? Would that one have to tie into the black balance lead that does get used? Am I making this more difficult than it is?