Andy released the hostages who were mostly King's Defense combat personnel, but he still held No. 3, Leonid, John, and Kevin.
Gao Guang believed that Andy had deliberately chosen these hostages. He wanted the nuclear weapon, so No. 3 had to stay in his hands. Leonid was his manager—doing arms deals would be impossible without Leonid.
John was Gao Guang's oldest ally, the foundation of his empire, without exception.
Kevin, needless to say, managed Gao Guang's finances. If Kevin were captured and spilled everything, Gao Guang wouldn't even have a single usable account left, not even a penny in savings.
Although Gao Guang couldn't use bank transfers for handling money right now, having money frozen in accounts is still different from having them completely drained.
Even Andy's people weren't monolithic—they naturally divided into two factions. Andy handed the less important hostages to underlings he planned to eliminate and assigned the crucial ones to Black Box for safekeeping.