http://www.fiba.basketball/basketballworldcup/2019/asian-qualifiers/howtoqualify

How teams advance from the Second Round to the FIBA Basketball World Cup 2019

The three (3) best placed teams from each group and the best 4th-placed team (total of seven (7) teams) shall
qualify for the FIBA Basketball World Cup 2019. For the FIBA Basketball World Cup 2019 Qualifiers, to determine
the final standings, the FIBA Basketball World Cup 2019 Host, China, shall not be included. However all results
related to the previous games of China in the relevant group shall be taken into account for the final standings.

上位3位が勝ち抜け。その後、4位のチームの内、成績良い方がWCに進む。中国は順位には考慮しない。

だから選考では中国が3位以内とか何位になるとかは考慮されない。中国除いた5チームのうちの3位までが確定で、
4位は日本がいるグループの4位と比較するだけ。