Start by having one person surviving against one attacker and once they are in contact the third person starts to walk toward the surviving one with a stick or knife aimed at him. This will help the survivor to pay attention to his surroundings and keep moving. You stop moving and you get a knife to the side or a stick to the head and very soon you either start to pay attention or stop moving altogether. After you do this for a while do the drill with one eye closed and find a way to stay relaxed with a lesser field of sight.
