Roguey
Josh seems to be misinformed, since no one has yet observed enemies actually taking a hit from Disengagement Attacks. That's because Disengagement Attacks are so ludicrously strong that Disengaging is a choice the AI never makes. He's basing part of his assessment on scenarios that don't actually occur in practice.
For that reason, any player Talents or Abilities based upon strengthening their Disengagement attacks are absolutely useless in any scenario, and since Josh was on a crusade to avoid useless abilities, he failed miserably in this context.
In general, the Engagement system is much more advantageous for enemies than it is for the player's party, since many of them are melee-oriented... unless of course you spend 20 hours' worth of stingily parceled-out game money creating a party full of Fighters and/or Barbarians.
There's a whole thread about the Engagement system in which some very well-written analyses pretty much definitively powernuke the whole idea and implementation as being misguided and clunky.
That's the point of contention with Shadows. They get to bypass Engagement seemingly at-will, then deal truckloads of Disengagement damage to the weak characters they teleport in to target. It needs fixing, not because it's too hard or because anyone can't win those battles, but because it's fake difficulty and complete garbage game design. If Shadows weren't bog-standard trash mobs plastered all over the largest area at the beginning of the game, and were rarer or a special encounter, that'd be something different.
I don't have a problem with characters I dress in tissue-paper armor getting wrecked if my lines are breached. I have a problem with teleporting trash mobs who enjoy the full advantages of the Engagement system while suffering none of the consequences, and hit like trucks.