Brumby
Major
Peter Tomka, Slovakia
Bernardo Sepúlveda Amor, Mexiko
Hisashi Owada, Japan
Ronny Abraham, France
Sir Kenneth Keith, NZL
Sir Christopher Greenwood, GB
Joan E. Donoghue, US
Giorgio Gaja, Italy
Dalveer Bhandari, India
9 out of 15 Judges are definitely not pro China, plus Vietnam can appoint an ad hoc judge for this tribunal. There will be 10 out of 16 judges, who are definitely not pro China.
China has nothing to gain, if it calls for the ICJ.
You are making an accusatory statement that the appointed judges will not make decisions based on recognized standards of law or justice but instead will have pre conceived bias against a particular person or entity. This is a definition of a kangaroo court even though you do not want to call it as such.