When I saw the title of this thread I thought it was interesting.
My mind immediately jumped to: if you attack and defeat all defenders in one round and they defenders did not score any hits, then the attacker can proceed to attack the next territory in line regardless of movement points left.
The idea, as I thought of it, would be to blow through pickets and attack territories of value, maybe get defenders to actually defend territory?
Might not work, just what immediately jumped to mind.
I don’t think you could ever use it in this case, unless there is only 1 or maybe 2 infantry defending. No matter how huge an army you have built up, if the defender puts at least 3 infantry to guard, they are likely to get at least 1 hit. So you could have 50 infantry, 30 artillery, 30 mechs and 20 tanks to roll over any defense but because of that single defending infantry hit, your whole monster army is stalled.