I agree, we used to carry navigators with sextants on the RAF Britannias. I did a polar trainer in 1971, with SpecN navs at the end of their Manby Course and a Litton 51 on board. We flew from Thule to the North Pole, orbited for about 20 minutes while checking compasses etc then set off for Brize Norton and landed 9 hours later.. One thing that came out well was the Smiths Flight System and our magnetic compass.