According to the rules of arcane fulcrums, the wizard occupying them is immune to multiple wounds. Yet at the same time, when I read about Storm of Magic battle reports, I frequently read about cannons being a feared wizard killer. Wouldn't a cannon do a max of one wound or does the protection from multiple wounds only apply to multiple wound attacks in close combat?
I don't have the current rule book on me, but I recall in one of the older editions that a model could be killed in one hit if the strength of the attack was twice that of their toughness. So a S10 attack from a cannon could kill a flimsy T3 wizard, regardless of the amount of wounds on the wizards profile.
I think 8th edition removed that rule. As far as Storms of Magic go, I am not sure. I know that if a slann is on the Fulcrum, he gets a 2+ or 3+ ward save. That alone should save him.