Clarke described Tomkins as a "freewheeling" character well equipped to do the job.
"He is a one-in-20-years player," said Clarke, whose brother Phil was a superb Wigan, Sydney Roosters and England forward.
"Sam is the best player out of England since Ellery Hanley. When I say best, some might say Andy Farrell or Paul Sculthorpe. But Sam has that X-factor, like Hanley. His performances in the last three or four years, the ability to make something out of nothing, are fabulous.
"He's stood up to anything thrown at him. He copped physical and verbal attacks - opponents really target him and he used to get a lot of abuse from away fans trying to put him off. None of it fazed him."
Warriors recruitment boss Dean Bell and chief executive Wayne Scurrah made the crucial visit to England when Tomkins was persuaded to sign. Tomkins told the Herald the Junior Warriors' regular success was a major attraction, indicating the club was positioned for an upward climb. He also liked the family atmosphere.
Four Australian clubs showed interest although one was in a location Tomkins didn't fancy, and another quickly faded from the chase. The Titans are believed to have been in the final hunt. Clarke said the Warriors built a case whereas the others struggled to back up promises.
"Obviously money was an important part," said Clarke.
To put a final stamp on the deal, Tomkins' mother Alison and a friend checked out Auckland and gave it the thumbs up.
"I'm a bit of a mummy's boy ... her opinion was never going to make or break the deal but it did help," said Tomkins. "Wigan is quite small and I really like going to London and Manchester ... I'm looking forward to living in a bigger place. I want to be part of creating something big at the Warriors. I will put in 110 per cent."
One of Tomkins' oldest school friends will also shift to Auckland, and the opening 2014 NRL clash will be against the Eels, who have recruited Lee Mossop, the Wigan prop.
The Warriors' welcoming committee includes Tomkins' old Wigan buddy Thomas Leuluai, whose unreserved recommendation to coach Matthew Elliott fired the Warriors' pursuit of Tomkins.