Indians and Koreans have had experience of both
The vast majority of the Indians in both world wars faught with distinction and served well on British merchant ships. However there were a few bad apples as there are in any national group. The worst Indian I read of was a Bengali named Nataji Subas Chandra Bose. After WW2 Clive Street in Calcutta was renamed after him. Prewar he went to Germany and sucked up to the Nazis but the Germans had no time for him and sent out of the country. In Singapore he recruited some Indians to his INA Indian National Army who faught for the Japanese in Burma. "On to Delhi." was his slogan, they were stopped at Imphal.
The Japanese sent Bose to Port Blair in the Andamans where he was not admired and then to Burma where many Burmese disliked Indians. Seeing the defeat of his group coming Bose tried to Fly to Japan but was allegedly killed in a plane crash. Good riddance.
Never been to Korea but have had negative experience on ships and ashore with them. To me they are less honest than the Japanese. If North and South Korea ever join they will be a menace in my opinion.