Well, my idea of the avalanch was only to summon big rocks falling at enemies, not the summon of a stone titan's model throwing them (let's face, in the movies they were just to big for giants, were more like titans haha). However, the roaring sounds of those giants would be cool only for the sake of giving the power a great sound. But looks that we won't seem something like that power become real, cause as DieWalkure said edain team is not interested and they don't like the stone giants concept. I don't like that concept for the mod too, that is why my idea was only to have the rocks falling in the battlefield.
Now, the idea of BOTFA's command centre is really good, that thing would need to give really good bonuses for all units in the battlefield considering we are talking of the second 10 points spellbook. Or maybe it could have an own palantir with many orders that affect all units in battlefield, in the movie that command center was moving along with Azog's orders. What abilities and effects will be in that palantir, I'm not sure, but they have to be "orders-related". Also, aesthethically, it would be a nice thing to see in-game.