It'll be very interesting to see how Cheika approaches the Rugby Championship. Obviously with so little time before the WC kicks off, you want to settle on your best team pretty quickly and get as much consistency as possible. At the same time, Cheika needs to somehow address the following issues:-
1. Giving test experience to our reserve THPs.
2. Trying out 1 or more lock or no.6.
3. Giving Cooper a run.
1. Even if Alexander is taken to England, I think we're still better off to plan for a different TH on the bench and use Alexander as an injury back-up at best. For my money Greg Holmes should be our bench THP during most of the rugby championship, and possibly be given a start at some stage (resting Kepu for 1 game).
2. It remains to be seen whether Horwill is still in the selection frame, but I'm assuming Cheika is at least considering trying out 1 lock in the RC and seeing how they fair. I'd put Coleman on the bench for maybe 2 of our 4 games.
I'd also consider resting Fardy for one game and giving Timani a start. The impression I get from Timani is that he'll look right at home at test level. He loves hard work and physicality.
3. Depending on Cooper's fitness/form situation. I'd like to see him get at least one game starting at 10. probably the last games of the RC against Argentina. If you don't start him any one of those games, you might as well leave him out of the WC squad because he's not going to have enough quality rugby under his belt to be useful.