This works for other terrain features as well. I can move into charge position under cover, etc. Take this to an extreme. . .Imagine having a forest stretch along the middle of the table from edge of deployment zone to edge of deployment zone. Some armies will have a difficult time keeping the opponent guessing after deployment. Bretonians will have the most difficult.
Wood Elves have the easiest time. .
If the wardancers attack will they attack using shadow's coil. . The incredible manuevrability of the Wood elves along with the variety of attacks they can present and roles the units can play should keep an opponent second guessing your intentions all game long. As a unit, perhaps nothing can compare to the giant for the sheer flexibility of his role. Characters are the absolute hardest items on the playing board to predict. Leave 'em guessing.