As it is, a stockpile of snow can easily counter any attempts at snowball attacks. As such, snowballs should take away snow from a snow stockpile upon impact. This lets us construct snow fortresses and have snowball fights.
One piece of snow easily blocking any possible counterattacks:
This is a great problem, literally unplayable. With this feature added our beautiful hearthlands may have great snowball fights. An artist's depiction is displayed below.