How exactly? Can you describe the scheme?
Put any Necromancer with Expert Necromancy + Cloak of the Undead King (60%) into a Castle. Attack with 10000 Liches. Clone them and die. The AI raises 12000 Liches. Kill them with 100% Necromancy and get 12000 Zombies. (+20% out of nowhere) And if you make the AI clone them, you'll get 24000! (+140%) That's the whole math. And here you are going on about millions... :D