The magic and magic skills implementation is currently a stub.
There will be possible for a lord specialized in magic to fight on even grounds with a lord specialized in heroic skills.
Instead of passive permanent buffs to soldiers, magic lords will use powerful spells during combat, more then one cast per turn, multi targeted spells etc to increase the effectiveness of their troops.
As with the heroic skills, magic skills will augment the power of a lord's army, not compensate for the lack of it.