Right now, stacking up on the boss is a good way to counter this bug if your DPS cannot move into the boss quickly enough, but then your melee DPS have trouble killing the adds, unless you always move the boss on top of the adds, which adds challenge to your tanks but makes the healers' job easier.
I agree that best way of doing it is stacking on the boss.
But if you do it in the middle of the room, you have adds close to you no matter which direction they come from. Most melee has some kind of gap closer (i think only vanguards have "Hold The Line" which is not that great) but sentinels can force leap, shadows can Force Speed to adds, Scoundrels can roll towards adds etc etc.
Not to mention that melee adds come to your group anyway so get range to kill healers, let melee adds get close to your healers then tank AoE taunt and you nuke them ...