Subtract MPPT efficiency losses of about 5-10% for MPPT wiring and controller.
For parallel 12V panels with PWM use Isc with no panel to controller wiring loss as the panels are about 18V output. HOWEVER panel amps rise with panel temperature hence at noonish and say 140F panel temperature PWM has a advantage. Vmp decreases with panel temperature. The panel temperature compensation for voltage loss is greater than that for amps gain.
Point being that with all of the variables it's involved to compare various configurations with the same equipment.
