Yes 18 people in alliance can easily destroy this, or if they choose, FARM the currency like crazy if anyone has any good idea left to NOT just zerg everything and move on lol. But there lies also the problem, there are only so many roots (since wasp nest giving you a rather horrid currency) to destroy. Even if the alliance ends up destroying roots and nest, that would not leave enough for other people or smaller group to participate. Unless you love having 36 people in one spot - remember how small that area is - and dealing with horrible lag. SE never really tell us anything on how we are suppose to do this.
I posted earlier that I suspect these roots is your own camping - farming spots and the idea is not to destroy it too fast but hold it as long as you can - to farm currency. But the general ideas that everyone is doing is just zerg and move on, which leave you run around finding the next root to destroy. Not really great when you are not the only 12-18 people who also want to do this in one zone. Just imagine if everyone is swarming SoA... We will have a bunch of afk on follow waiting an hour for a tree to spawn only to kill in 3 mnts and back to afk
