If the White Hand will be fixed in a patch, might I suggest you also make its followers evil and not neutral? Taranis adopted it and became neutral in my game.
Also, I think Taranis should also be given the Ice Touched trait, and automatically spread the White Hand to his cities like Hyborem with the Ashen Veil.
And perhaps you could balance the AC decreasing by spreading the White Hand by having the Illian/Frozed rituals plus building Fiacra increase it. A small amount for Fiacra, but larger amounts for the rituals, increasingly so as one approaches the Draw and finally, Ascension.