It's not the hero class that prevents learning spells, but the presence of the Blood Wrath skill. By the way, if you pre-assign spells to a hero with Blood Wrath, they will be able to use them.
For now, I'm still leaning towards the idea of making a barbarian without spells and summons (giving him a high chance of attack and defense). But it's a very large project, so I'll put it aside for the future.
Added 7 minutes ago
No, the Orcish spellbook is a separate matter; you can't assign spells to it. But if you pre-assign spells to a hero of another class and give them Blood Wrath, the spells will work (but they won't be able to learn new ones).
Added 24 minutes ago
But if you pre-assign spells to a hero of another class and give them Blood Wrath, the spells will work (but they won't be able to learn new ones).
I tried... it doesn't work (the spellbook is empty) =)
