So I'm writing a Star Wars fic and the rebels are having a strategy meeting between skirmishes. They're positioned underneath a shield with a mile radius and the streets are barricaded. They know the enemy's probably going to send in walkers pretty soon, since they're more maneuverable than tanks. Of course these are city streets so we're not talking something big like the AT-ATs from the battle of Hoth, but something closer to the AT-STs from Endor. The rebels' solution is to decrease the shield radius, tightening the space between it and the barricades so the walkers don't have room to blast them apart. But the barricades aren't evenly spaced, so there are points where a walker could, at the very least, stick its nose through the shield and get a shot at the barricade. How can the rebels conceivably defend these weak points?