True. But there are other sites to check too. As has been said, Campagnolo came up with the idea of offering full component sets as a "gruppo" fairly recently in terms of bicycle history. What? Early 60's as the Record group? Since then, it's only really been SunTour and Shimano to offer sets as a group set, AFAIK. And perhaps a couple of obscure French companies.

Iab mentioned a very good resource on the subject. The Dancing Chain, by Frank Berto. Well worth a look, OP.