I don't know what you are talking about Mike. 1/3 of the ogres live through purple. How is that killing an army? You still get look out's on your characters from purple. If anything purple will be lucky to kill 4/6 ogres. Not all death wizards ride around on horses either. Purple on the flank is best case scenario. Throw in something random like pit of shades with a scatter and I would be lucky to hit more than 3 ogres. And that is only vs low initiative targets. You are taking a 1500 point unit and crying that something might be able to kill it. I don't understand the reasoning at all especially when in reality I would be lucky to get 2/3 of the unit barring I don't misfire or fail to roll far enough on the artillery.
We should go back to 7th edition when there was more balance in the universe. :P