Acolytes can't cast spells.. ever heard of the cult of the damned? acolyte were normal peasants, then kelthuzad, called by the lich king, spreaded a new occult religion secretly in the cities, the cult of the damned, made of normal villagers but believing in the lich king as being a god started the plague ( the human campaign, very first missions ) with the help of magical cauldrons.
those villagers didnt learned magic, very far from it. they're only humans that dedicated their life to the lich king, they did not learned necromancy or any spells at all.
all i can say with the picture apart from an apparant lack of knowledge from the author: it seems very laggy, and some doodads are either misplaced, wrongly coordinated or there are way too much of them.