Quote Originally Posted by Derio View Post
Ultimately the decision falls on the healer. If the healer feels like they can take on more adds then they depict the pace. DPS should never depict the pace unless things are melting so fast that the tank is taking next to 0 damage which is rarely the case.
Not quite, it is actually a combined Tank-Healer decision, with the default being "try as much as possible and go from there". An inexperienced tank or healer can both reach a critical level of being unable to sustain the pull, usually due to lack of player experience and making the most out of their cooldowns, while a veteran tank or healer can make up for that with incredible resource and cooldown control.

This is of course assuming the DPS players are actually not grossly underperforming and making pulls last too long.