3 man to or from Europe is fine if it's a daylight flight for the crew both ways.
But throw in a night flight both ways ,with a midnight or later departure from HK and a possible difficult winter approach in Europe things start to get interesting .
Even that could possibly be managed if the crews weren't operating very close to 100 hours every month , and everyone was getting 4-5 days off before and after the flight , accumulated fatigue will become a major factor
To say nothing of the lack of flexibility of crews should someone go sick . Somehow I suspect that a number of pilots will call sick with fatigue .
What will happen should Guanghou create delays for all traffic departing HK Europe bound , ?
File as many AsRFs as you can