werecorpse
Adventurer
Ok, here are my answers to what you asked.
1) The grab manoeuver will be used to manoeuver a PC out of formation. Example: PCs are in a 10' corridor. The two tanks are blocking the way so that only one giant is able to attack. Perfect tactic from the group. The giant will grab the pc, turn and drop him behind him. Now the PC might give advantage to his buddy. But the giants are in advantage to attack him too. The same goes for hobgoblins, orcs and many other monsters. Even owl bears can do that.
Aah now I understand, you play the flanking gives advantage DMG variant. We don't.