BTW If you fancy some sport and want to open another can of worms you might want to ask why BA don't need/aren't recruiting DEPs direct onto the 747 as well...........
AFAIK, ten DEPs were recruited straight onto the -400. Don't know the whys or wherefores but I would assume they were already type-rated. Suffice to say, there are (more than) sufficient valid internal bids onto it so it's politically easier for BA to type-rate existing employees rather than train new joiners and cause a mutiny.