Intra Europe *G will only give you one piece extra if you bought a 'classic' or 'flex' fare with LH/OS/SN/LX. If in economy you get 23 Kg / 50 Lb extra that way. Business gives 2x 32Kg/70Lb anyway and *G one piece of 32 Kg more. If you buy a 'light' fare, you get no luggage and no *G extras.

In China you will get some extra on CA, but the *G number has to be in the reservation.

Switching around FFP numbers carries some hazards and might not work well reliably.