It seems to me that the major point of the AS glyph is the difference between Add pulling and Boss pulling.
Add pulling = multiple targets
100% dmg to all three targets
Pull aggro + 100% X 3 > Pull aggro + 200% X 1
Even with two targets...
Pull aggro + 100% X 2 = Pull aggro + 200% X 1
And only one target gets the 200%, so the other is more likely to get pulled off unless you do some fast tanking.
However, suppose there is only one man to pull...say, a boss.
You get double damage from the attack, which comes out as double TPS
Pull aggro + 200% X 1 > Pull aggro + 100% X 1 (only one target)
I myself have not glyphed this. This glyph is more for a boss-tanking MT than an add-tanking OT, and I perfer Judgement because I use it more in my rotation, but the choice personal and situational.
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Many fall, but one remains. - The Stranger
Men are but flesh and blood. They know their doom, but not the hour. - Patrick Stewart
Thornir