My speciality is thinking of ideas. Not all of them good, but I hope this might be of use.

Here's a suggestions for that.

A little like in real life, not committing players and conceding a ruck leaves the attack not as many options but to attempt forward runs chewing up a metre or two more than usual and grinding it up the field. So the attacking player may find in that instance that for the while that the defence employs that tactic, forward runs from the attacker can be tackled but the forward player drags an extra metre or two than normal and is less likely to be turned over. So in that instance the defence would have to land a very good tackle on them to either cause a spill or increase the chance of a turnover. This whole tactic would add a little dimension to forward play.

Meanwhile some members of that defensive line might come up a little more aggressively on back line moves whenever the first five (or further out) gets the ball. This could be due to having the confidence of more players in their defensive line and they could either smash the attacking player or on the other hand they might leave a hole where they rushed up a little too much from their zone of the field. A well timed pass to the left or right by the attacking player would hopefully reach a player who may have a chance of exploiting that new gap.

The idea you guys have sounds good, so I had to try and suggest something to make it more viable!