Reinout,
Thanks for the reply. I had not read that about Wolff and Richthofen. I've become interested in the tactics used by the pilots as the war progressed. By 1918, everybody had figured out what worked, I would think, and the obvious utility of the two man element must have occurred to someone.
I'm not at home so I don't have my notes or books, but I remember 3 or 4 pilots of a French squadron which flew together using mutual support to attack ballons and I've read that the Kests used quite complex tactics attacking the British bombers of the
Independent Force.