from another WSJ article:

The insurer-paid firefighters say they don’t favor more expensive properties during a fire, but give priority to client properties that are most at risk, whatever their value. They generally don’t directly battle blazes. Instead, their crews try to get to client homes ahead of a fire, sealing off vents to keep embers from getting in, moving combustibles away from the structure, and sometimes spraying fire-retardant gel on the house.