the melee adds can be taunted, even lurker can be taunted.
i basically go to where the melee adds spawns, then follows them.
the moment when you can see the adds coming, it is actually just graphics, you cannot do any hostile action to it, it is only when the adds stops, then they actually begin to "exist", and i can taunt them right away. it's kind of like when oddbob mc's a guy in a pull, when we are killing that guy last, i'll stand right in front of it and spam taunt, and once oddbob let go of mc, the taunt goes off so it doesnt hit oddbob.
as long as the tanks can position correctly when the melee adds comes out, it should be simple. I've seen a pally offtank video where the pally first stuns the guardian then consecrate to establish aggro.