Would it make sense that NRL clubs were affiliated to a particular SL club. Then if they have a young talent who they arent ready to blood in the first team just yet, but can see that he has real potential they could 'loan' him to their SL club for a season or two. Thus giving him the experience he requires plus proving he has what it takes, also the SL club could well get a real talent at a vastly reduced cost?!
Obviously it wouldn't be as simple as that with contracts and loan periods etc. But its just an idea....