Doesn't matter how you try to cut it, Green at half or 5/8 he will never play in the halves with Smith, it would be the slowest halves combination in league.
Firstly, Morris had a reasonably successful 2005 outside Smith, forget the game against the Cowboys, if you use that as a guide you would sack 3/4 of the side that won the minor premiership whic is more than was hoped for at the start of the season.
As for Green, I doubt that he will make a permaent PL player let alone 1st grade. I think his best chance is to try and develop into a hooker.
Players like Hayne & Inu have shown some promise in JF but have also show their inexperience at time, I've witnessed a couple of shockers from Inu in particular. Hayne certainly looks to have more ability at this stage but both need to work on their physical strength if the are to take a permanent role in PL.