While it is correct that the history and reach of B & S is global and complicated https://www.swire.com/ourjourney/tablet/en/index.php
China Navigation was along with Jardine Mathesons one of the two most upmarket shipping companies based in Hong Kong. Lesser mortals worked for the 'outside' companies such as Yick Fung and Ocean Tramps.
Officers ( UK , Aust and NZ ) were employed out of Hong Kong with Hong Kong conditions. Crews were Hong Kong chinese. Ships - esp in the early post war years after they quit mainland China and before they became involved in the Pacific Rim trades to PNG etc - traded out of Hong Kong.
They had some ships involved in the cross trades within the cross trades..... Anshun after coming off the Hong Kong - Australia liner trade was on the Hadj from Malaysia to Jeddah in the season and went latter day 'blackbirding' around the SW Pacific for the rest of the year.... picking up contract labour from the out islands and taking them to Christmas and Ocean Islands to work for the Phosphate Commision.https://www.theshipslist.com/ships/lines/cnc.shtml
Interesting photo in that first link of an ex ANL 'B' boat in Taikoo Dock......