True, but what we know currently suggests that the Insignia of the Grand Army isn't affected by the "Unique-Equipped: Legion Legendary (1)", it might still be added, but I think that's unlikely since the last batch of legendaries had that tag on PTR, so it'll probably be our actual third legendary... or fourth in the premise of this thread.
On the latter: I love the helm, but T21 set bonuses and T19 two piece set bonus seem to have some insane damage potential.