This also explains why all the spells I did find even with their complexity it's still mostly symbols as they can't use many things to base the spell on. furthermore, this would make it extremely hard to make a basic healing spell as it would have to be almost entirely symbols weakening the final spells effects rendering the spell almost useless. This even explains why this world still teaches mostly traditional healing and many other methods my old world used as you can't just heal anything as the number of ponies that know and can use powerful healing spells are probably in extremely high demand but low number.