I was always under the impression that Tanks - certainly in Group content - were about making sure it was THEM that took the kicking, rather than the rest of the Group... so that the rest of the group that weren't tasked with making sure the Group survived the encounter in as great shape as possible meted out a kicking on whatever was preventing the Group getting to the final objective.Nowhere did I see that Tanks had to be doing significant damage, unless they were on their own... usually levelling or doing WQ, etc. Granted, a Tank needs to be doing 'some damage' by way of making sure the current bad guy focusses their ire on the Tank, but surely as long as that's happening, all's good.As far as any Group content I do Tank goes - usually only World Bosses and the occasional 'free-for-all' that constitutes the heftier WQ's - Tanks might just as well not be there, 'cos the encounter usually degenerates into a "genital comparison contest" with scant - if any - regard for the role your Class/Spec. is intended for.Now; my guess would be that this article is NOT intended to be 'consumed' by the 'more-than-moderately-capable' in the fields of Raiding &/or M+, being that Tanks featuring in the top 10 of any damage report means they're being relied on too much &/or the setup is sufficiently familiar with each other to know what needs doing, by who & when... so anyone outside of these fields of endeavour would have reason to raise issue, if whatever needs to 'get dead' ain't obliging in short enough order. That said, if any given Tank DOES outlast whatever they need to dispatch, again - all's good; but if it's taking too long, then, yes; more damage is required.
