On reflection, I suppose there might even being an argument against armour. One can attack SWA pretty violently with, say, a spade without penetrating the armour, but goodness knows what damage will have been done to the inner cores and/or their insulation.Having the live conductors surrounded by earthed metalwork is considered an acceptable means of protection for burried cables. The earthed metalwork does not have to be an armor.
Kind Regards, John
