If New Zealand and England, who also have plenty of big forwards, can play to their strengths and launch a continuous barrage of big men through the middle at tiring defences, it will help them get a roll-on and they could be hard to stop.
That's something hooker Issac Luke can exploit, particularly on the back of a quick play-the-ball. But there's also the danger of the big men tiring, which will allow smaller, smarter and fitter guys to take advantage of any holes.
It's how Australia are attacking this World Cup. They have picked only three recognised front rowers, using the likes of Paul Gallen, Sam Thaiday and Josh Papalii as props when they need to, and also have Cameron Smith who is the master of controlling a game out of dummy half.
New Zealand have some very big men and they need to be careful, and that's where the likes of Simon Mannering, Elijah Taylor and Sonny Bill Williams, who are all very fit, need to tie things up and slow the ruck speed.
Even though I am a Kiwis selector, I have no influence over who Kearney picks for each game.
Once the team go into camp, it's all up to the coaching staff of Kearney, Ivan Cleary and Tony Iro. They are living and breathing it and know what to do and they are three smart operators.
That said, it's time they started playing their best 17. They have had a look at everyone now except, of course, Thomas Leuluai who has been injured but with 30 tests under his belt they know what he can do.
It's now about developing combinations and confidence.
The win against France last weekend was a decent one, particularly defensively, but there is still room for a lot of improvement in attack.
It looked like they tried to force things and moved away from the game plan that will win this World Cup.
They went wide too quickly without having done the work through the middle and lacked polish and rhythm. League is a simple game and the Kiwis would do well to keep things simple.
