in an open field, fighting against AI stacks that are initially so much stronger is almost suicidal. A Pyrrhic victory over one AI won't allow you to win against the subsequent ones. The Knight has little mana to restore damaged stacks. Magic isn't a natural skill either. Under these conditions, light magic in an "open field" won't save you strategically. By the way, is the "leadership crown" a built-in artifact on the map, or was I just lucky?

Added 6 minutes later
by the way, the "divine retribution" skill, which belongs to one of the sisters, isn't very useful in defensive battles, and the Knight's native skill, "preparation," is completely useless, since there are enough troops anyway, and on this map, everything is fine with gold. The Gnomes didn't rush to return the copies that the scout had captured in their dungeon.