On spells stopping bullets, for every defense there is a counter.
I remember once, can't remember the name of the book, but some orcs found a cache of machine guns. The wizards on the other side figured out that the guns were not magical and created a bullet stopping spell. The orcs responded by adding anti-magic talismans to their guns and mowed down the wizards.
I'm not sure what you'd call it in the UK, but here we call it one-up-manship. How much of that are you really going to have in your universe?
I remember once, can't remember the name of the book, but some orcs found a cache of machine guns. The wizards on the other side figured out that the guns were not magical and created a bullet stopping spell. The orcs responded by adding anti-magic talismans to their guns and mowed down the wizards.
I'm not sure what you'd call it in the UK, but here we call it one-up-manship. How much of that are you really going to have in your universe?