Help, Why do I lose aggro when healer cast regen?

[Synol]

In add situations PLD and WAR are left with virtually no tools to deter monsters from targeting an over zealous healer. Flash and Overpower can't outpace Healing AOE enmity generated in 8 man groups. WHM can spam it's high enmity heavy Cure III/Cure II/Medica II and effectively take hate and hold it - I've had PUG WHM's brag they're "tanking" but it only lasts until their MP is diminished.

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I tend to cast Stoneskin on a tank so they have time to generate aggro on a pull but occasionally they run in when a regen is still on. Good tanks still get aggro easily, scrubs do not. If you've had WHM's brag they are tanking it is because you are simply a horrendous player.