That's a fair point, but not one that really worries me as you'd be using a unit that cost, what, 100 points? 200 points? To take out a 25 point model on a 50 point gun. Your doing so would save the other 2100 points of my army getting hurt from one of your beat stick units. That 2100 points can then turn on your guys and unleash hell.
Secondly, the Harbingers of the Storm are equipped to discourage from your
DS'ing too close, as by doing so you take
d6 S8 hits. This happens also if you charge in to combat with a unit they're in, meaning your best option is to stand and shoot them. Depending on positioning, I'd be able to bring between 20 and 40 shots per unit of warriors (potentially 60 to 120) back at you.
So perhaps Farsights best option to charge in