I suppose judging from period and location that Hsiao Yao (2) and (3) are probably the same person
http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng
http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng

and wouldn't feel surprised if
Stephen So (2) http://hkmdb.com/db/people/view.mhtml?i ... y_set=big5 and / or
Joseph Siu Yiu http://hkmdb.com/db/people/view.mhtml?i ... ay_set=eng are related to him (them)

We should wait to find portrait captures of (3) movies.

I checked EIGHT ROBBERS and did not find Siu Yiu - but my copy is very dark and has bad image quality, and also many cast members have fake beards

We need to find the other 2 movies.