wrong... healing only does not make any mob entering the fight, so someone must have been on top of the aggro list before me... think about it. I am not opening any fight and i am not adding any other mobs by attaking, so i can only get aggro from mobs that have had aggro on another player.
There is no magic in it...
As a healer i am producing aggro on ALL mobs that are involved in a fight. So now explain why guarding the healer will not at least give the healer little more time until these other mobs are starting to attack the healer ?
of course... again... explain please why guarding the healer will not extend the time until all these mobs are going after me...
but you are right... it`s not worth to discuss about it...
Just a few points. First, someone else may initiate combat, either by proximity (Body agro) or deliberately (Pulling).
From that point on, any action that adds a new buff to a party member, heals a player that has taken damage (effective healing) or deals damage to a hostile target. Will be considered the top priority for the target. Whether the tank has attacked the mob or not.
Example: You are the healer and have guard. Tank pulls a pack of 5 mobs. 4 mobs are clustered and one weak mob is set apart from the group. You cast force shield on the tank followed by rejuvenate.
During the first few seconds of the pull, all of the mobs including the standalone weak mob have been attacking the tank.
However, none of the dps or the tank have landed any blows on that one weak mob.
The moment you cast your shield on the tank, the weak mob switches to you. The first tick from rejuvenate created additional threat on the threat table of the weak mob. Now, having guard on you means that with your own passive talents, (assuming you are healing spec). The amount of threat you produced was lower than with out guard.
But because no one else has landed a blow on the weak mob, the weak mob will continue to attack you as you are still sole and top threat on the list. Despite all of your threat reduction from talents and guard. You still have 100% of the weak mob's threat.
The solution to this example is quite easy, as I already stated. Healers have passive threat reduction built into their talents. Healing threat is also based on effective healing and can partly be mitigated by using absorb mechanics like force shield.
Either the tank or the dps just has to hit the mob and exceed the small amount of threat you have produced to cause the mob to attack the tank or dps that attacked it.
Put simply, most dps and tanks tunnel vision.