I think what G-CIVC might be referring to is 77G has a higher pax to crew ratio than 77H.

At least among FAs, I know it is a huge bummer to get Y class (versus J) on 77G, because of the substantially significant workload. Since it often just comes down to their overall J class ratio to determine their position for the flight, it is seen as a serious case of bad luck to get assigned Y on 77G. For 77H the workload disparity b/w Y and J is not as great. So if you get J on 77G it's a sigh of relief. Beyond the 77W crew rest area, 77G and its workflow is a despised plane in Y class for the FA.

For CX to have things set up as so, it really is just asking for the FAs to offer crappier service on 77G. More than half 77W flights are 77H, and besides it is an easy gig to do J class on 77G. You could literally be an FP (or BC, etc) and fly to JFK and do Y or J without too much care, yet a few weeks later go back to EWR on the 77G....and flip a coin if you have to sweat your backside for 16 hours (Y) or take it easy (J), have a nice flight and offer great service to few pax to boot. All for the exactly identical pay, except for the significantly lower ground allowance in EWR. Sure it isn't right, but logically I get why Y class FAs on 77G aren't always the happiest campers. It only goes so far to blame the FAs...at the end of the day, if the system isn't designed too brilliantly, the higher echelons are to blame and the customers pay the price. But then again....some of these longhaul Y fares are DIRT cheap...get what you pay for I guess!