Realism is an abstract we can try to put ourselves into a a submariner. All it means for me is using the least amount of help from the AI. There is no way I can feel what it's like to be depth charged. We might have some reference points from our own lives to use, like combat, but we are not going to feel the
terror.
I play the hand that is dealt. If it means loosing a favorite captain, so be it. I try to learn from my failures. I think reality is playing the spirit of the game.
FWIW