In that case, depending on how the 6P P42A battery is made, and assuming 4 wheel drive, (all of this is relevant)
In the maximum I would use 12AWG to each ESC (10AWG to each pair of ESCs / or to each dual ESC), and 12AWG for the phase wiring.
In the minimum, I would use 14 AWG to each ESC (12AWG to each pair of ESCs / or to each dual ESC) and 12AWG or 14AWG for the phase wiring. In a 4WD configuration you can probably easily slide by with less, but I just personally wouldn’t do less.
For your battery series connections, in the maximum, I’d use triple 12AWG and in the minimum I’d use triple 16AWG.
You can also get by just fine by using 12AWG for everything, simplifying your purchasing greatly, by doubling it up on the battery series connections and doing 12AWG everywhere.