Re Cartwright as a back up, it is a great position to be in. It means if he is in the team as a lock we don't need to carry a back on the bench. Yeo and CH can cover the centres and wing at a pinch, Carty the halves, Peachey can cover the backrow. Its a very versatile, mobile pack of forwards.
If he gets back to being lock, it gives us options to spread the ball wide very quickly with him at first receiver. He has a great long cutout pass that can be used to get the ball out to Moysa or Cleary.
The Raiders of the 90's used to use Daley and Stewart to do something similar. They covered the whole field with two spiral passes that had speed and power. Not a big arced, floaty "lob" like a lot of players use, that gives the defence time for an intercept and to adjust in defence. Instead of Meninga waiting in the centres when the ball arrives by spiral delivery, we have Blake and CH or Yeo. Tantalising thought.