“Not sure how much difference that would have made with the winds they are dealing with.”
Probably none. Windblown embers can travel a very long way. They land on shake roofs or get sucked into the attic vents of tile roofs.
The approaching wall of fire can be 50 ft high or more, and things ignite well ahead of it. Radiant heat transmits through windows and sets fire to the interior.
That can be true, and was true in some cases. But in many cases in Santa Rosa there was no wall of fire. There were unburned trees and even unburned houses in the middle of burned houses. That suggests mostly windblown embers (your first thought). Most of the roofs were not shake, but asphalt shingle, probably class A, probably did not catch. But the houses had many entry points at vents, soffits, siding joints. Many houses that burned had indented corners while a plain square house next to it did not burn.