I grouped up with 1-2 healers and another DPS (I play as feral) and got a winstreak of 8 or 9 as alliance in Silvershard Mines. It is definitely horde biased, but it is possible to win as alliance if you just get people to follow your tactic of rushing everyone to lava and sending 1 DK or pala to top if feasible (look at how far along the top cart is and when the BG starts). If done correctly you will cap the top cart and if you are good you will also get the lava cart. The key is to stop the horde before they can get more than 1-2 people onto the lava cart circle. My favorite thing to do is using Ursol's Vortex on the hordes as they all come rushing out of their spawn and turn right to get to the cart. They'll all get slowed down and dragged back to the vortex once, thus giving you enough time to get a few people onto the circle (warrior with leap etc.). Of course you could be the victim of this tactic as alliance as well but... Also use any chance to stun people outside the circle of influence or knock them out. I have no count of how many times I've ninja capped the mid cart by stealthing, using typhoon, vortex / stun on a solo or duo of defenders just a few seconds before it gets capped.