I've come across a sneaky combination in the new O&G book. The signature spell in the Little Waaagh! (goblin lore) is called Naughty Stabbing, and grants the targetted unit Armor Piercing attacks, and the ability to re-roll failed To Hit and To Wound rolls, but only if you're attacking the enemy in the flank or rear. Now, the easiest way to get a flank or rear charge in is to make use of flyers, and it just happens that one of our most destructive units is a flying monster that has dropped dramatically in points.
So why not combine a Warboss with plenty of attacks at effectively S7, flying a Wyvern, with a cheap Night Goblin Shaman there to buff him with the Naughty Stabbing spell? Re-roll all those 2's to hit, and 1's to wound - you even get to re-roll your thunderstomp attacks! Now, if only you would get to re-roll the dice for the amount of thunderstomps attacks you make. I swear I never roll as many 1's as when I'm rolling for my thunderstomp.