I think, especially with named spells, we should tilt to wizards. Even if it gives them way more spells. Part of the wizard iconic aspects is spellbooks and it assumes a lot of spells to copy.
If anything, when the dispute is heavy we should opt to tag the spell for creation of a new spell for both classes and just fight over the spell name like Aggy's Scorcher.
If anything, when the dispute is heavy we should opt to tag the spell for creation of a new spell for both classes and just fight over the spell name like Aggy's Scorcher.