As another thought on 2 person flight deck rule why is there no problem with the EK B777F flying around most of the time with 2 crew??
I'd rather fly 2 crew than with some horse grooms from somewhere deep down in Kashmere.
But then again, they must be thoroughly screened and vetted and must pose a smaller risk than our wives .... (Quote from one of our managers stating this very reason as to why they can't fly with us as passengers, like on any civilised freighter worldwide)
It's basically simple: The rule of this topic
increases the risk!