[GK3]

My neighbor's son is the crew boss of a Washington State Forest Service firefighter team. They specialize in fighting mountain forest fires. They had been stationed in SoCal for a couple weeks in December, then returned to Washington. Drove down again and have been assigned to the Eaton fire. I'm sure other teams from Washington are there now, too.

Thank him and his team for their service. Why were they here in December?

I was wrong, it was in November overlapping Thanksgiving, and ironically they were positioned there as an immediately available resource because of the anticipated fire danger from Santa Ana winds!

Very common for the FS to move its crews around to where they are needed.  This time of year they can move them from lots of places since the fire danger is pretty close to zero around much of the country at the moment. At the same time fire crews tend to be seasonally employed so there are probably fewer availible. As you point, out their crews, at least back in the day, are trained to fight timber fires first, brush second, not structures.  So it would certainly make sense to have them working the mountains and brush covered hillsides.  Terrain, fuel load and structures will to a great extent dictate tactics, what can be done and what can't.  Spot fires from embers carried aloft by the brobdingnagian winds can fall on roofs near and far.  If you have a dried out shingle or other similar roof covering your risk goes way up.
Spot fires are very complex, here is a sample of the kind of considerations involved:
https://www.sciencedirect.com/science/ar...1222001084
if you are dealing with timber fires: https://www.nwcg.gov/publications/pms437...e-behavior
One last article reflecting that spot fires can occur 40 kms from the main fire: https://www.csiro.au/en/news/all/article...respotting
Even in grass fires in the Midwest, spoting can occur a mile from the front. 
You can see that defending a big fire driven by big winds and making its own big winds is extremely complex and difficult. You don't just pull up your flat bed, drive off the dozer and start building line immediately in front of the fire.  There are a good number of universities that offer doctorates n Fire Science, Range Land Management etc.  Places like Oregon State, University of Washington and many others.  When I came back from SE Asia I was accepted into the doctoral program at Washington, but I was tired of no money and the thought of three more years of little money led me in other directions. The science of the subject is still of interest.
Now it seems winds may be back and that is hardly good news.

[GK3]

My neighbor's son is the crew boss of a Washington State Forest Service firefighter team. They specialize in fighting mountain forest fires. They had been stationed in SoCal for a couple weeks in December, then returned to Washington. Drove down again and have been assigned to the Eaton fire. I'm sure other teams from Washington are there now, too.

Thank him and his team for their service. Why were they here in December?

I was wrong, it was in November overlapping Thanksgiving, and ironically they were positioned there as an immediately available resource because of the anticipated fire danger from Santa Ana winds!

Very common for the FS to move its crews around to where they are needed.  This time of year they can move them from lots of places since the fire danger is pretty close to zero around much of the country at the moment. At the same time fire crews tend to be seasonally employed so there are probably fewer availible. As you point, out their crews, at least back in the day, are trained to fight timber fires first, brush second, not structures.  So it would certainly make sense to have them working the mountains and brush covered hillsides.  Terrain, fuel load and structures will to a great extent dictate tactics, what can be done and what can't.  Spot fires from embers carried aloft by the brobdingnagian winds can fall on roofs near and far.  If you have a dried out shingle or other similar roof covering your risk goes way up.
Spot fires are very complex, here is a sample of the kind of considerations involved:
https://www.sciencedirect.com/science/ar...1222001084
if you are dealing with timber fires: https://www.nwcg.gov/publications/pms437...e-behavior
One last article reflecting that spot fires can occur 40 kms from the main fire: https://www.csiro.au/en/news/all/article...respotting
Even in grass fires in the Midwest, spoting can occur a mile from the front. 
You can see that defending a big fire driven by big winds and making its own big winds is extremely complex and difficult. You don't just pull up your flat bed, drive off the dozer and start building line immediately in front of the fire.  There are a good number of universities that offer doctorates n Fire Science, Range Land Management etc.  Places like Oregon State, University of Washington and many others.  When I came back from SE Asia I was accepted into the doctoral program at Washington, but I was tired of no money and the thought of three more years of little money led me in other directions. The science of the subject is still of interest.
Now it seems winds may be back and that is hardly good news.