By the time that Barry and his group of upstart revolutionaries got in their positions, the veil of dust and smoke would begin dissipating. Those things don't stay around forever. The cloud, although stopped the Republic forces from having a visual on them, also worked the same in reverse, but it was beginning to thin out, and Barry and his followers can spot the enemy tank and are aware of where the speeders are that are on the look out for them, but the same isn't is in reverse. Because they haven't told bellowed where they are at to the Republic forces. Upon having visual of the tank, tank barrel is pointed away from them, but their missile launcher on the side of the turret is exposed. Since it's lightly armored and still loaded with explosive bunker busters, it's a vulnerable target. Barry would order his men to fire on that missile rack. Barry would also join in on the shooting as well as his revolutionaries are firing. . The tank is within thirty meters, therefore in range of the rebel's pistols. The rebels might be toting pistols, but blaster bolts still nonetheless have this nasty habit of exploding when they land. Barry would also fire off fast-paced rounds as quickly as he can with his burst-fire rifle while keeping careful aim on the target. Harlam might be in a bit of a situation, but there isn't much Barry can do. He will just have to hold out. Barry's course of action, means he just given away his position. The missile launcher should be destroyed soon (since the Wompa is "lightly armored" and the turrets of tanks tend to be lightly armored than the rest of the vehicle), making the missiles explode and taking the top of the tank with it. Of course Barry and his men aren't oblivious to the troopers and speeders, and are ready to react to them as needed. If the tank's main gun starts turning towards him, he is of course prepared to get away. The Barry and his men are spread out across the front of the building firing from the window. It shouldn't be easy to single out the former RJF trooper.