First, it should be in "You made da call", but I suppose it's going to be moved there
Otherwise, refer to page 41 of the
BRB:
If the majority of the target unit is obscured from the shooting model's view, it counts as being in cover. Of course, a unit is not obscured by itself (meaning that the back ranks are not obscured by the front ones)
Intervening models (friend or foe) give a -2 to hit
The width of the intervening unit compared to the shooters and target is relevant of course (a single infantry model won't usually be able to obscure a full unit being targeted)
But it would need to be some serious bad-ass dogs to obscure most of the (tall)
WoC unit from the view of the (tall) Elven bowmen!