About 40 years ago, British Caledonian operated Edinburgh-Copenhagen and Glasgow-Stockholm (or it might have been the other way round), in both cases via Newcastle, using the BAC 1-11.
The timings were such that passengers could change flights at Newcastle, so BCal effectively ran flights to both Scandinavian capitals from both of Scotland's major cities.
A bit like 9W at BRU. So the "scissor hub" concept is not a particularly recent invention!