You guys need to read up on your AFTLs!
The HKG>DAC>HAN pattern will need to change, and will most likely be split up in DAC or HAN, only CX knows where. My bet is DAC, since it would be such a lovely place to overnight.
You can not reasonably roster that pattern with four pilots. The pattern starts at 9:00 sign on, so your max FDP is 12.5hrs. You can extend it with inflight rest, but remember that rest can only be calculated by subtracting 1hr from the sector. The DAC>HAN and HAN>HKG are very short sectors, so it would be very hard to achieve sufficient rest for all four crew.
This would be okay if you wanted to burn out a couple of the guys, but you can't do that. 15.5(E) says that if you finish your relief duty, all time after that can be classed as positioning (ie, what some guys call "burn you out"). But again, this is the freighter, so you can't position on the freighter, so you can't use this provision. Every member of the 4 man crew would need to be achieving the required rest, for which there is not enough time to make the pattern work, since the FDP could only be extended by half of the total inflight rest of the crew member who gets the least amount of it.
Clear as mud?
One other option, would be to operate the pattern with 4 freighter PX biatches (ie, someone who has signed the offer). Then, they can continue to crew it in the same manner. That is why GMA's offer contained a contingency for "if they get enough biatches". This is that contingency. Cathay loves "as is" solutions.