Manly flyer Tolu Koula says his focus is now on becoming one of the world’s best centres, after several brief dalliances with the Sea Eagles’ No.1 jersey. Koula will bring up his 100th NRL game in Manly’s must-win clash with the Dolphins on Friday night, having turned into one of the sport’s strike outside backs. Manly teammate Haumole Olakau’atu this week warned it was “scary” how good Koula could be, adamant the 23-year-old can become the game…