Ok. So no matter what the natural casting roll is you have to at least roll the casting value to dispell... Dispel range is clear... Just keep your distance an cast what you can...
The problem in "keeping the distance", is that you cast spells in your hero phase, before moving. So, the enemy sees where your casters are, and can move his casters to counter you (or can directly try to attack them).
Now, you shouldn't build your tactic around it, but sometime you can effectively counter enemy's magic.
Real game example: I've got my block of saurus warriors, backed by Sunblood and Starseer, advancing toward the centre.
My enemy was an Ogre army, that was trying to lure me in the range of his butcher.
Now, the last thing i wanted, was to see my horde, being chomped away by the maws, so i used my move to place my starpriest (buffed with curse of fate) at 18" from his butcher. It costed me resources, but, tnx to curse of fate and cosmic herald, his butcher didn't cast a single spell in all the game.
You need to be careful with your movements and plannings, if you want to cast without being countered, and be able to counter enemy's magic.
(at least, this is if we speak about magical attacks. Magic that buffs units, is easier to cast, and harder to counter, because casters usually stay in safer positions).
The previous list of tzeentch, doesn't fear counterspells: they can cast too many spells, there's no way the opponent can counter 'em all.
EDIT: I've edited my Tomb Kings review, adding the Necrotect. On a second thought, the guy is simply too amazing to don't include it!
