I like basic LOS blocking walls.. even a simple Fog Bank can disrupt LOS between a mage and his Battleforge, making him unable to take advantage of the extra actions/equips that he was counting on.
I always run some sort of wall in just about every build just for harassing ranged units like Gorgon Archers (who are slow and then have to drag around them), to block wizards LOS from things they want to teleport, to block off LOS from Temple of Light, .. as far as Ive seen its honestly one of the most under utilized and most important aspects of disruption. An etherial Wall outright ruins Akiros Hammer too, which is fun.