Airborne drones can't carry enough water to be useful for extinguishment, but land-based drones could, and a swarm of mini-bulldozers to clear a fireline would

Airborne drones can't carry enough water to be useful for extinguishment, but land-based drones could, and a swarm of mini-bulldozers to clear a fireline would be even better. Getting them to work reliably in rough terrain with lots of vegetation would be a big challenge though.