How do you gain it when SEAD type missions would be constantly needed against hundreds of drones which cost a fraction of the cost of the munitions used against them?

Shit dude, there are a lot of possibilities out there.Airlauch your own drone swarm to give it extra range. Produce drones with further range, better accuracy, and better explosives. Electronic warfare to stop enemy swarms. That's just off the top of my stoned head.