It's a bit of a coin flip which one starts, but both make the team, right? Piakura would have more impact, coming fresh from the bench, so that's one reason to start Jetski.
Mariner is a compulsive try scorer. He's in my team for that reason alone.
I'd like this, but I wouldn't be shocked at all to see Billy at 14.
Only other change I could see is Jetski starting and Piaks off the bench. Jetski to take the early stint and brunt of defence.
What I think will happen:
1. Walsh
2. Cobbo
3. Staggs(if not injured)
4. Mariner
5. Arthars
6. Hunt
7. Reynolds
8. Carrigan
9. Piax
10. Haas
11. Gosiewski
12. Riki
13. Hethrington
14. Walters
15. Jensen
16. Willison
17. Piakura
I think even though Piakura did well he will commit to him as a bench 2nd rower for impact, going for a more safe team to start the season.