Thats a bit of a stretch. There are 90 buildings in a town.
I wrote "keep down", not "take down". And that's no stretch.
One big blob will hit here & there, taking out large portions of a town, then dissipating instantly if any resistance is met.
THEN it will take just one player every 30 mins or so to make sure the timer for town doesn't start. And thus any defending side will inevitably end up with having to safeguard a lot of maprooms at once. Who's going to do that?
And because that's an easy way to completely disorganize and surprise the defenders, it will happen. It will grossly unbalance the game, no doubt about that.