[narwan]

You know the system can't do specific damage like that.
The only thing I can think about is to give the weapons a HEAT score to use instead of the HE value. In earlier versions that wouldn't work because HEAT rounds only had and AT effect and no HE effect, but the latest versions have added a limited HE effect to HEAT rounds. Perhaps by giving it a HEAT value it's possible to simulate the effect vs armored targets (knocking out the radar would effectively mean the unit is 'destroyed' as far as the game mechanics are concerned) and by increasing the HE side-effect of the HEAT round (increasing warhead or HEK perhaps) the weapons might still be as effective against non-armored targets as they are now.
I don't know if it's possible at all code-wise, that's up to the designers to decide, and whether the improvement would be worth the work involved but that's the only way I can see to get the SEAD game-mechanic a bit closer to 'reality', assuming that the result even is closer to reality.

Narwan