Chiefs officials have revealed a family barbecue in western Sydney and a personal plea from Papua New Guinea Prime Minister James Marape helped them land the historic and prized signature of Jarome Luai. A day after Wests Tigers co-captain Luai spoke about wanting to create a legacy by signing a three-year, $3.6 million, tax-free deal with the NRL’s 19th team, the Chiefs explained why Luai was their key target. The Chiefs also hosed down concerns about the tax concessions, after Bulldogs general manager Phil Gould questioned whether the financial incentives even existed on his Six Tackles With Gus podcast. Chiefs general manager of football Michael Chammas picked up the phone to Luai several weeks ago, but upped the ante when he invited the playmaker and his family to his home last Saturday. The pair live in the same suburb in the Penrith region.…