Each pack weighs about 900kg, so when it comes to scrum time they're always going to be shunting each other backwards & forwards, making it pretty much impossible for the halfback to put the ball into the tunnel straight... reckon the 9 that has possession deserves to roll the ball in a bit closer to his own hookers feet.
These pedantic/complicated scrum laws are ludicrous... scrummaging was at it's best when both packs just engaged themselves, without refs interfering with this ready, steady, go crap, also a halfback knows much better than a referee when to feed the ball into a scrum.