G777,
What you say is indeed true however I think you haven't taken into account the training requirement and the training load. It is easier to back fill the 777 with DEP pilots than to train up Airbus pilots who then leave a 'hole' in the Airbus fleet which will also have to be filled by a DEP.
If the cadet scheme were up and running then those holes could be filled with cadets to enable them to get the cycles in. The cadet scheme isn't running and the costs point towards back filling this year and posting NV for the next Cassandra run (next month!)
As said, never say never, but also never believe Cassandra, they only publish ONE run but the system runs every day!