Elliott Management’s arrival is the latest twist in a trans-Atlantic deal drama. Investors in U.K. plastic-packaging maker RPC Group are right to be dubious that the American hedge fund can secure a higher offer for the company. Paul Singer’s activist hedge fund said Thursday in a filing that it now owned 8% of RPC, which supplies tubs and containers to consumer companies like Nestlé, Procter & Gamble and Beiersdorf.