I'm not familiar with Australian vegetation and fire screening technology, but a relatively simple measure you can employ is creating a network of firebreaks around and in between your paddocks. This doesn't stop the panic and air pollution in case of a fire, but at least it might save the lives of your horses.
As long as it's hot and dry, vegetation growth is stopped or slowed down. This gives you the chance to create effective firebreaks that stay intact for a few months.
The easiest way to create your own firebreaks is to plough around the area your want to protect. The firebreak must be at least 1 meter wide in open grass land, wider in forested areas, and must be freed of any remaining flammable substances like roots, leaves or grass. It's best to plough very deep, really tear the ground up and turn the soil over to make sure any approaching fire can only reach mineral soil, but no flammable vegetation.
If you can move the paddock fences, I suggest moving them inwards on all sides, then ploughing the perimeter of your paddocks and in between each one (just in case, better safe than sorry).
If you cannot move the fences and the soil is packed and vegetation is thick, it might be better to plough the same firebreak twice to remove as much flammable material as possible. Keep some distance to any trees or bushes remaining there. Adding more firebreaks in increasing distances helps if embers are blown across one of them anyways.
If you happen to have paddocks next to eucalyptus woods, I would preemptively evacuate them.