found out, that Director Sin Wi-Gyun 申謂均 [The Gwoi-Cho Guru (1981), Assistant Director for: Postman Strikes Back (1982)]
and long-time Assistant Director "Chin Wei-Chun" 申渭鈞 to famed director Cheng Chang-Ho (10 movies coopration) are the same person - maybe somebody likes to know about that change- result see:
https://hkmdb.com/db/people/view.mhtml? ... ay_set=eng

If I don't got it completly wrong (https://movie.daum.net/person/main?personId=334) he was also involved in the making of:
"The Dead and the Deadly" (1982) and "The Challenge of the Lady Ninja" (producer: Cheng Chang-Ho, again!) (1982)