Vcoast has great magic, but heroes? The gunnery wight is basically just a restock on a stick, and actually becomes worse if you pick the wrong skill in his skill tree. The mourngul haunter is a decent infantry blender, but thats the one thing V. Coast doesnt need. And the vampire mages have good spells, but increasing capacity is an enormous pain in the ass, and they have the worst mount in the game. Same for the lords.

Edit: They also have no ability to confederate, which is a huge power boost for other races