Fanatics don't need tactics. What would they need them for? They just spin in your general direction and cause immense havoc.
I recently played my first ever game of Warhammer Fantasy (hooray), and unfortunately against Night Goblins. I learnt personally that Fanatics are a pain in the puffy pants, and I couldn't find any way to bypass being hit by their large, metal balls. You can't target them as they're hidden in the Goblin unit, and if you get within 8" of the unit, Release the Fanatics!
Is there any way to avoid Fanatics? What tactics can be used against Fanatics?