Well what to pair with Fire...Rad of course.
Its overpowered and who does not want to be overpowered.
Besides it is fun to irradiated them and watch them burn.
Frads FTW all the time. Trollers, Blasters, Tanks, Brutes, Srappers, Corr. All of them, nuke them till they glow and burn them to ash its the only way to be sure they are clean.