The "Finger Four" was standard through the war but flights and squadrons positions varied; until 1944 when the enemy coast was reached they formed line-abreast stepped up and down, as in diagram 2. Aircraft in a flight were about 750 ft. apart, the distance still able to read code letters. Then sections of 2 flights parallel, until the bombers were reached when the squadron (4 flights) formed around the box.
Flight = 4 aircraft, Squadron = 16, Group = 48.
Nick
formations by
Nicholas King, on Flickr