Backfires not really that effective in 60-70 mph winds (from former Hurricane Dora). Hurricane Fernanda headed towards Hawaii now:
https://www.nhc.noaa.gov/refresh/graphics_ep2+shtml/203641.shtml?gm_track#contents
https://zoom.earth/maps/satellite/#view=25.6,-147.6,3.83z
I saw a pretty big grass fire put out by having M-88 Armored Recovery Vehicles form a line 90 degrees to the fire and drop their blades and button up and go full speed through the fire and grass while jigging left and right.
They were on hand and manned.
Not much you can do with big fires.