??? you don't get anything from the auras compared to dual grief damage

Its called opinion.ol dont get mad cuz i asked a question.

When only 1 variable is discussed (damage), there are no opinions, but only facts.

Things are different if you talk about different features, like damage and %mf and total life or resistance, and max block, and absorb...
In this case, different playstyles may lead to different answers. Any opinion counts here.

Back to topic :
1) Grief without might aura gives (much) more damage than last wish with might aura.
2) Frenzy barbarian with Griefs do have might aura, at a higher level than what last wish provides. It is given by his mercenary (as you already pointed out in the first post).

I strongly advice for 2 x Grief (Grief + Death in populated games), for the highest damage output.