Gums
Not to diminish the real navigators, but many "system operators" in the back seat were not well trained to actually "navigate". Maybe some folks that flew early Phantoms and other interceptors can comment.
As I recall it in the early 80’s the RAF navigators on the Phantom had all gone through some form of core navigation course (at RAF Finningley) which included the likes of Astro........so yes, they had been trained in the dark arts before progressing to mastering the enigma of the B-scope....