Reasoning about this discussion, I don’t remember if, in Aurora, nuclear explosions also generate electromagnetic pulses (EMP) as they do in real life.
If not, could this effect be added?
Its energy should be proportional to the warhead; but we could think of specialised WH, to increase EMP energy, and smaller other effects.
Armour could reduce its effects. And in case of a planetary bombardment, entrenchment would help too.
Electronic hardening should further reduce EMP effects on the systems, reducing the probability of a damage (e.g., a 100-faces dice could be rolled to decide the outcome).