damage/healing occur simultaneously
When attacking/defending stage has been completed. All attack damage and lifelink healing should occur simultaneously. but it seems like on the pc platform at least. it only happens left to right so say if 5 creatures are attacking and the damage going thru will put opponent to zero health. but one blocking creature has lifelink then if that blocking creature is blocking the first, leftmost creature the lifelink will go thru and opponent will not be defeated, but if the blocking creature blocks the rightmost attacking creature the opponent will not incur the lifelink and will be defeated. All the damage and healing should be delivered and occur simultaneously, regardless of the animation, that represents the action.