In progressive linkage, the Main carb is the rear, it opens its primaries which has to feed all eight cylinders, and is responsible for most of the idle tuning, then it opens the Front carbs primaries, and then secondary's on rear carb finally the secondary's on front carb progressively opening them in sequence or exponentially to have all eight open at WOT.

The eddy carbs tend to be a bit lean anyway so the rear carb needs to have bigger jets to try and compensate.

I rather have both front and rear work in unison or tandem. Cross rams work with 1:1 because each carb feeds a different bank, this would be the same principle if the plenums were split which they almost are with this intake.

Havent you heard most guys cant seem to tune a six pack worth a dang, Thank the progressive type of linkage and tuning carbs for different jobs on the same engine.