technically, I could run both pos and neg off a simple power post for each.. and that is still a possibility if the busbar proves too big..
all the power is just coming from the 10 gauge red, a single source... the power is being fed to the series of circuit breakers behind the switches... which yes, you could piggyback all the feed sides of the breakers with a series of jumpers...
if i can fit the bus bar, it just gives me that added flexability of some extra hookup spots, but isn't a necessity..