The loss to the British game of
its superstar player,
the man who sprinkles stardust on Super League, further underlines the seemingly irreversible trend of our top players moving to Australasia.
The move was on the cards from the moment Wigan legend Dean Bell - the Auckland side's first ever captain in 1995 - came to talk to Tomkins four months ago, although only this month did Wigan finally accept they could not keep hold of the England full-back for even one more year.
Bell met Tomkins and Wigan's chairman Ian Lenagan to set the wheels in motion after the player admitted he wanted to leave. Another man who has played for both clubs, Kiwi international Thomas Leuluai, then played a key role.
Sam's Super League story
Scores five tries on Wigan Warriors debut in Challenge Cup tie against Whitehaven.
Named in Super League's Dream Team for the first time. Scores three tries on international debut for England against Wales.
Scores in Grand Final win against St Helens as Wigan claim their first title since 1998. Equals England record for tries in a single Test match, crossing four times against France.
Plays in Wigan's Challenge Cup win over Leeds Rhinos at Wembley. Signs new five-year contract on the same day his older brother Joel swaps codes to join Saracens. Makes first rugby union appearance, playing on the wing for Barbarians against Australia at Twickenham.
Wins League Leaders' Shield with Wigan. Ends season with 36 tries and is voted Super League's Man of Steel for the first time. Becomes England's all-time leading try scorer.
Equals club record by scoring in 11 consecutive matches for Wigan. Scores last-minute try in Wigan's Challenge Cup final win against Hull FC at Wembley. Named in Super League's Dream Team for fifth year in succession.
"Tommy said 'you'll never make a better signing in the history of the club'," New Zealand Warriors chief executive Wayne Scurrah said. "He doesn't say those things lightly and the homework we've done confirms that."
Scurrah also confirmed that the traffic between England and Australia is now more or less one-way.
"There aren't many top-flight NRL players who will go to Super League," he told me. "That's a difficulty they'll have to work through. While they've got a good product, they've got to work out the commercial base that can afford the players of the highest calibre."
This is a far from controversial judgement on a competition that remains without a main sponsor, but it is a situation compounded by the movement of big names in the other direction.
Lenagan puts a positive gloss on the situation, despite the fact he will lose both Tomkins and England prop Lee Mossop next year to a vibrant Australian game buoyed by a massive TV deal.
"Australia envies the quality of the players we are producing," he said. "For the players, the attraction is that the money there is better."
The Wigan chairman also cites the fact his club have first refusal on Tomkins if he opts to return - though the player remains keen to play union at some point in his career. And he says the cash raised from the transfer - "a nice cheque for us" - will be fed straight back into the club through the backroom staff, facilities, education and sports science.
It may surprise Super League fans that Scurrah was as impressed with Tomkins the man as he was with Tomkins the player.
"He's a fabulous competitor and that's what struck me - what a great person he was and his desire to do well and prove himself against some of the best in the world."
Archive: Highlights of Tomkins' 2012 Man of Steel season
Tomkins - as naturally gifted a player as I have seen in Super League - is likely to be a major success in the NRL. He has a chess player's mind with boxer's feet and the kind of free-flowing arrogant brilliance that makes Ronnie O'Sullivan the king of snooker.
Tomkins may still return to this country, but union seems the more likely future option. And meanwhile there will be more big moves down under. I understand there is interest in Tomkins' team-mate and Super League's top try scorer Josh Charnley, while Leeds and England centre Kallum Watkins is learning to deal with questions about a move in the same manner as Tomkins did this season.
Can Super League still compete with the NRL? Lenagan, positive though he remains, admits it is now tough despite the appeal of the on-field product.
"Playing standards are comparable - certainly the top five Super League clubs are as good as anything in the NRL - but as the national game in Australia is rugby league, there are Premier League-type television deals."
The bottom line for Super League players is that it is a short and brutal career. The Australian game is currently marketed far better than the British game and the exchange rate there is a huge carrot to earn a better living.
And as Lenagan points out, in the same way that interest in league players from rugby union is a huge pat on the back for the sport, the desire from top Aussie and Kiwi clubs to buy British is equally flattering - whether the attention is welcome or not.
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