What good are amulets if the Dungeon faction has the innate skill "Unstoppable Magic"? They remove 75% of magical protection on Expert difficulty. So, with artifacts, whether you focus on magical protection or not, it doesn't matter to the Dungeon faction.
2. 75% is at the Absolute level; you still need to reach that level. On Expert difficulty, it's 50%.
3. "Unstoppable Magic" removes protection, but not resistance. If magic is used and it doesn't work, what will the poor elves do? They'll have to enlist in the skeletons...