Fylde Warrior, you now seem to be flailing desperately and repeating yourself several times over but not responding to the points I raised or the questions I asked you.
The NRL is certainly a competition with more consistently high standards from team to team. No one would deny that. But to describe Super League as a second-tier competition is silly, as Super League's record in the World Club Challenge demonstrates. I admit that it may prove difficult to keep up that record as the financial disparity grows between the two competitions, but that is in the future, not the past.
And it's a non-sequitur to say that the best individual player, year by year, must always be an NRL player, just as it would be to say that the best soccer player in the world must always come from the highest paid league.
And on the subject of individual players, it's worth noting, for example, that Luke Burgess couldn't break into the Leeds team, but featured consistently in the starting lineup for South Sydney in 2013, helping them to third place in the league. So the disparity in standards doesn't seem as great as you seem to imagine.
Your arguments are all hypothetical, while you seem to think that actual evidence of clubs' and players' attainments doesn't count.

Did Sinfield play on his own for the Leeds Rhinos? No wonder they've won that many SL titles from 5th

His international credibility is a subjective opinion, yours is he lacks it. Most people would probably think that your opinion lacks credibility, especially the corner you have painted yourself into regarding England and Leeds Rhino’s especially has led to some fairly incredulous opinions that you have put forth. But both my opinion on your credibility and yours on Kevin Sinfields are irrelevant because it is impossible to say what would have happened because they didn’t play, it is unarguable fact, that Australia’s decision not to play, and the disappointingly potical proposal from NZ did deprive Kevin Sinfield of the opportunity for international success against the major southern hemisphere sides and as such it is clearly correct to say that it wasn’t his fault he didn’t have success against those nations this year.

Sinfield did experience international success this year by the way. The international game doesn’t start and stop with the Australians, however much they, and their fanboys believe it does.

Perhaps he was denied. He's won MOM the last two times England have played New Zealand over here. If we could've had a 3 game England vs NZ series their's a good chance he might have been Man of the Series.

Who awarded him Man of the Match in the game played in England?