Despite having Improved Knockdown and Improved Disarm, the Doom Knights only use Knockdown, as they have that feat as well in their feat least. Could it be removed so that they start using IKD? Or are they not even meant to have IKD?
It's been reported many times. I don't think many of the summoning themes will be adjusted any time soon as it's a pain in the ass!
The illusory doom knights are incredibly powerful, no need to change it.