A late neighbor of mine was a B-24 pilot (Ploesti 2x), and he used to chuckle over that myth. He said that saying implied you could one-hand a Liberator in a tight box formation, which as far as he was concerned was a joke. He said especially if you were tail end Charlie, it was a two handed affair and you left the throttle jockeying to your copilot and flight engineer at your command. He said that (and plenty of "stick time") sharpened copilots up pretty quickly and improved them to the point they could become replacement aircraft commanders. Not the way it was taught in training command, where the skipper drove the bird and the copilot operated the gear and flaps, sat on his hands, and stood by for emergencies.
He said by the second half of his tour he was Squadron Commander, and always flew lead, so everyone formated on him. He advanced so quickly, unfortunately, due to high attrition amongst the leadership and few experienced replacements. Ten months from 2nd Louie to Brevet Light Colonel.
Cheers,
Wes