Or you can use the multitude of other DE options to shoot the crap out of redirectors. You can always charge the cauldron out of the unit to take care of redirectors. Remember, they're core, and elf core isn't the best, combat-wise sometimes volume helps with that. And if you are really worried about those units, just don't charge the witches into them use something else. And if you can put on a couple wounds against knights, that's a lot of points you can make up for when they cut down your numbers. Regarding tougher enemies like knights or heavies, sometimes the sheer volume of attacks that they have to save against can still put on a couple unsaved wounds.
So only 28% (not 50%)of your attacks will be wasted, which can sometimes be worth it to have an extra rank of supporting attacks. With a Witchbrew Death Hag, we're talking 39 S3 and 6 S4 poison attacks with ASF/Hatred and Murderous Prowess. Standard 5 wide still allows 7 wide worth of attacks. Not going to make much of a difference to knights or other infantry with T4 and at least a 4+ save. Sure, you have ASF and murderous prowess, but you're still only S3. Sure, they get a lot of attacks however, if they are in horde formation then the standard 5 wide units deny them half the attacks.
