Peter, You are correct. Your assessment is correct for the kit being considered. My recommendation would be more appropriate for multiple panel systems using an MPPT controller with the panels connected in series. An MPPT controller can handle the higher voltages from a series configuration. Thanks for catching that.
I installed my three-panel 185W system with a Morningstar PWM controller and used 10 AWG and 6 AWG. This was probably overkill, but I wanted to have some level of charging even in filtered sunlight. The wire was a bit pricey. BTW, all three panels have been attached to the roof with 3M VHB tape for over 3 years. I still check to see that they're still firmly bonded every time I wash the camper though.