I don't see the A320 as being as bad as it's made out. Going direct onto long haul isn't easy, for many reasons. The system does not seem to be very well designed to bring people from completely different airlines, different aircraft types and different flying environments (LH v SH) up to speed with flying a wide body across the globe out of LHR. They assign you 3 "training" trips (the quality of training can vary vastly from one trainer to the next), then a pre-check .. and then a check. A quick look at iBid can reveal how well this is working out with the sheer amount of additional training for new joiners, and command upgrades too interestingly enough.
In other words, on short haul they have a lot more sectors going about and the training can be more geared towards actual learning rather than rushed box ticking.