Not to knock the fire resistant features of 4S Ranch (they are built to a very good standard), but, as a long time resident of San Diego county, your assessment of how Santa Ana firestorms propagate is entirely wrong.

True, when they get started, they get blown primarily towards the west, but as a firestorm grows, it generates its own wind blowing in all directions outward from the hottest areas. Combine that with canyons which tend to funnel wind in directions other than East-West, and it’s very difficult to predict where a San Diego wildfire will go. Please check the maps for the Witch Creek fire, the Cedar fire, and others. Extensions of those fires ran both north and south of the main east-west axis of the blaze for well over 10 miles. In BOTH fires, the fire had fronts burning many miles both due south and due north of their ignition points. A wildfire started either in the Black Mountain area, or in the undeveloped hills and canyons south of Lake Hodges could very easily threaten 4S Ranch.