Wiring the way that diagram is set up won't accomplish anything better, unless you are worried about the wires downstream from the distribution block. The input for the distribution block will still only be a single 4 gauge wire (if I follow correctly).
Use this to help:
If you keep your runs short, you could use 8 gauge wire for your amps from the distribution block.
I ended up melting an 8 gauge wire that I was running a 500w rms amp off of while I was waiting for my 4 gauge wire to come in. But that was a long run, at least 12 feet.