However, in this instance, given a first officer on the flight deck and a captain banging on the door for re-admission, wouldn't that very hierarchy be more likely than not to have resulted in the captain being let back in? In this instance at least, would it not increase the probability of 150 lives being saved?
We don't know, it is as simple as that. If you think back to the JetBlue case it probably was a good decision not to let the captain back into the flight deck. In the Germanwings case it probably would have been a good decision to let him back in.
Die Welt on non-LH-group airlines in Germany
That article is kinda difficult for me. Some stuff is correct, some is quite wrong and some is distorted a lot. It starts with the oversimplification that every airline outside the Lufthansa group is pretty much the same as the one with the green logo in which the interviewed captain apparently works. There is a pretty wide variety of working conditions between very close to lufthansa to extremely bad.