CX has never been a joint business partner with BA and both already compete on the HKG-UK route.
Additionally CX already have direct flights to MAN (doing rather well as I understand) so I don't see why they would wish to route their passengers on LH via MUC/FRA?
Not sure what you seem to be seeing in here? CX can and already do partner with whoever they want (e.g. they already partner with BE in the UK).