When an opposing army brings in the big weapons, your kingdom has no choice but to ante up or fold - and a trained Battle Mage from the Guild of Arcane Combatants if nothing if not a big weapon. But what happens your generals and their generals have a common goal?
"It is said that among those people they have a loathsome custom- that they keep a spotted dog always waiting beside the gate of the yard where they bury the dead, and that in every funeral they allow this spotted dog to feast upon the dead, so that it grows fat and wise with the knowledge of the dead... Many necromancers do seek out these spotted dogs, and ask of them sciomantic knowledge, or take them as familiars." -Author unknown, "The Ways of the Necromancers"