The dragons in Astrea are based on jet fighters (an military craft in general). If you are familiar with these craft, you'll understand just how hazardous they are. It's not unusual for a ground tech on a carrier to get sucked into the air intake of a jet and literally disintegrated. It's not unusual at all for a jet (or other air vehicle) to go down, killing its pilot and anyone else on board. That's reality. That's the reality that I used to create verisimilitude in the Swan Song series.
As for promotions, that's also military. Especially in war, you were promoted through survival, and nobody asked your permission. That's why you have a chain of command. If the chain becomes broken, everyone knows who is supposed to step in. This sort of promotion by mortality was especially true in WW2 with the Army Air Corps. The losses were such that death meant promotion.
How is it that we can accept such brutality in real life, but in fantasy, such things become abhorrent? Holding up a mirror to reality shows us too closely what we truly are. We don't need to imagine a distopian fantasy world as we already live in one.