You pull you tank question.

[Reinha]

Low damage or low healing with high damage in is how you die.

Assumption. The damage may not be high enough to cause a wipe.

Healers and tanks do not have infinite sustain for any damage output to be fine. And tanks do not have infinite health and cooldowns for any healing output to be fine.

Assumption. Sustain and cooldowns can be enough for an additional pack.

When you have the choice between letting someone die or allowing them to potentially cause a wipe/an inconvenience to you or others in the party, that is what ypyt is.

Assumption. There can be a third choice: tanking the additional mobs, killing them, inconveniencing no one and progressing faster than you would have without the additional pull.

1 death is better than entire group wipe or messed up cooldowns in future pulls or a boss.

Assumption. 1 death can lead to further deaths and/or a slower duty completion time.

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Instead of making all these assumptions, ypyt tanks should test if they are correct. Keep tank stance on, tank everything and see if the group dies. It'll sting on the ego when you don't wipe and realise ypyt is the wrong approach but it's ok.