No, he’s right. Some packs are considered social and pull together no matter what, but often patrols and emissaries aren’t part of that pack even if they sit inside or pass through it. “Hard” pulls with damage will establish a threat table and pulse aggro all around them, but body or taunt pulling the periphery will only pull the linked mobs because no threat technically exists.
A good example is that massive pull in AD before Priestess, which usually has a Tides sitting in it ready to make fun times with uninterruptible wildfire and pyroblasts. Shoot any of them and the whole group comes – but taunt/body the far corner mob, and the Tides ignores you.
No. We use it when skipping Zaqul’s trash all the time.