AFAIK the finger-four formation (2 formations of two aircrafts each) is even in use today. It was invented by the Finnisch andthe Germans during the Spanish Civil War independently from each other.
http://en.wikipedia.org/wiki/Finger-four

The Luftwaffe continued the use of this formation during the Battle of Britain, in which its effectiveness was shown to be considerably greater than the standard three-aircraft "Vic" close formation used by the Royal Air Force (RAF). The RAF and later the United States Army Air Forces (USAAF) and Soviet Air Forces adopted this formation and used it themselves against the Luftwaffe. The Finnish Air Force proved the effectiveness by achieving a 16:1 kill ratio with the finger-four during the 1939-1940 Winter War against the Soviet Air Force, which at the time used the conventional Vic formation and superior aircraft.

If this were a unit on three Eldar lists, you would bet Chroma would have his eyeball on this thread and would be guiding its implementation or fighting the change (depending on what it was).