Everything went to hell on Starkiller as soon as Phasma was taken out. Why? Because she's the brains behind this whole operation. She causally manipulates Kylo and Hux into doing what she wants. Hux is a pretty figurehead who is useful for making speeches and distracting visiting officials, Kylo is usually loud but ineffectual (finding a map to one guy is going to change the war how, exactly? You do you, Kylo, and stay out of her way).