Colt, civilian crews are in huge organisations compared with small air force units. They don't live in each other's pockets, socialise off duty as a general rule of even necessarily know by sight all the others.
Perhaps in the post-war golden age with navigators, radio operators, engineers, and a cabin staff, with one crew flying multiple stages then the crew would be 'constituted' . Neville Schute wrote a novel on that basis, DC6 or similar aircraft.