To be fair, Jordan would dominate Sharman and go well in the Fox. He was going well in the Vulcans, has played Q-Cup and Elite 1 but without seeing the quality of Championship 1 sides, it's hard to say he's doing well due to it being of a particularly poor standard. Fox is probably the toughest amateur (mostly) comp in the Rugby League world, certainly the toughest physically anyway.
I doubt Jordan can sign on with Hull without spending a year or two playing in England first. I'm sure the foreign quota rules for ESL teams require them to have played something like 6 NRL games in the preceeding season. The Bulls had to get dispensation to sign Adam Henry for this year as he'd played 6 games for the Roosters in 2012 but the signing of Jennings and SBW combined with injury meant he had no NRL games in 2013. Jordan would have to qualify through residency surely and I can't see Hull using a foreign quota spot on him.
The pommy kid walks into the Bulls side because he's out on loan from Leeds, the Bulls were down to one fit prop thanks to injury, other loan props being recalled to their parent club and the fact that no professional player is going to sign to a club that's doomed to be relegated unless they have nowhere else to go like Jamal Fakir. It's not as straightforward as him not being able to crack the U20s but walking into an ESL side and the Bulls and London couldn't beat Mt Albert or Pt Chev on current form. He wouldn't get a look in at any other ESL club, not even London.