Dude I hope you didn't put this up just so in 12 months time you can say "I told you so."
Impossible to answer at the moment, however Shackleton is 27 and played City/Country last year while Galuvao is 31, last played rep footy in 2004 and Kingston is 26 and kind of a one trick pony (runs out of dummy half)
I'm not having a go at Galuvao or Kingston. They are great players. Galuvao played up a weight class for the backend of the season in the props department, while even if Kingston is a one trick pony, he's very, very good at it. All I am saying is Shackleton proved to be a good player in a crap team last year and if you're just putting this poll up as a pretext to having a go at him if he ends up a bust, then shame on you