The other thing is they are used to a rest every five minutes for a penalty. 1 penalty in a half is unheard of in Super League.
They also play more games. Kallum Watkins is playing his 33rd game today. The player with the most apperances in the Australia team this season (Morgan) is playing his 27th.
We seriously need to tackle this stupid idea that Super League clubs cannot be sustainable businesses unless they flog their players to the brink.