I also watched Sterlo, I thought Mathew Johns was spot on that Thomas Leuluai stifles our attack because he doesn't have the ball skills to be an effective NRL half. Johns said he'd be an outstanding hooker, which I also agree with.
So on what we've all seen...
Running game-Maloney wins easily
Passing game-Maloney wins easily
Kicking game-Maloney wins easily
Defence-Leuluai wins easily
I wonder what will happen when they get a few more troops on deck and are a bit more settled in the forwards, so can probably play around with things out the back a bit. To me Seijka is a raging hot favourite to take Leuluai's spot by the middle of the comp, and Tuimavave, while being a far worse defender, is certainly a far better ball runner and ball player. Maloney is easily the best 6 out of all them, and is seriously underrated by some here even though he was good for us for a long time, and IMO, Leuluai should go to the bench, and either Siejka or Tuimavave developed to give Johnson less attacking responsibilities. Seijka has an advantage to Tuimavave in that he's also a seriously good goal kicker.