Wouldn't it be possible to play differnt types of defence then Iafeta? start the game at a high tempo then chane it 20 minutes into the game?
Im sure Wiki would love to be a defencive captain or some sort of role like that.
I've never coached league, I've coached some other sports and in my book the key to most sport defences, be it football, or cricket, is footwork. And added to a combination defence like a team unit in league, communication. If you have good communication and leadership, you probably could adjust defensive strategies depending on the situation. Again though, that might be difficult to coach and provide too much confusion to younger players especially.
From what I've seen at games, I wouldn't mind employing a very compressed D that moves forward quickly when the opposition is inside their own 30 metre zone to cut down the ruck speed and the actual go forward, provided the wingers and fullback are weary of the chip kick and even the deep 40/20 attempt, from there to your own 20 a sliding D, and then in your own 20 an up and in style of D. From what I've seen, sliding D is a cautious and fairly safe defensive style, but it allows too much latitude and the ability to poke your nose through the line as opposed to the gang tackling, and when you're dealing with it from 10 metres out thats probably not a good thing. The key in footy I think though is communication, and committment to the plan - if you go the Roosters style of gang warfare up and in, if one player starts to slide, or comes up too quick, or doesn't come up hard enough, it creates opportunities either on the fringes or in behind the ruck.