The way it's set up, each bank of 3 cylinders has its own progressive 2bbl. The primaries go outboard to maximize the speed going past the secondary barrels for better atomization. The theory is sound, anyway...
Ah! That's right, these carbs plates don't open all at the same time. I was thinking trying to keep the throttle bores equidistant from the runners to maximize any tuning effect and to keep the mixture from the two bores from having to "bump into itself" and preventing droplet fallout.
