Well C would be a single pack (in a sense) because there'd be one connector and one balancer. I read on TrueRC that when assembling multi P packs that you should solder them all in parrallel first then in series, which seems to be the consensus here. I drew up a pic on paint for some visualization, one without balancers and one with. Not the best drawing I know, but you can see what I'm talking about.