OK, maybe it was a bit of a hyperbole to say 'obsessed', but why are Scandinavian Lutherans seen to be special regarding apostolic succession?
Because, of those churches which came into being or left Rome at the time of the Reformation, the Scandinavian Lutherans—like the Church of England—retained the apostolic succession. The continental Lutherans and Calvinists didn't. For some Anglican leaders in the ensuing centuries, that seemed to be a special bond that they shared with the Scandinavians.
Peteprint is 100 percent correct, and later we also have the Porvoo Communion which perhaps cements the bond: https://en.m.wikipedia.org/wiki/Porvoo_Communion
I think that part of the reason is that when it comes to a matter of the nature of orders we are in a similar position. https://rorate-caeli.blogspot.com/2008/06/question-of-lutheran-orders.html The article linked here is a Roman - and not favourable in approach, however there are a range of opinions on these matters. Scandinavian Lutherans adopted a more traditionally catholic approach to ecclesiology, as did a number of the Elizabethan reformers, so it is likely that there will be some common ground on which we walk. I think it is a long way from obsession for most of us, however.
It's funny that you used the word "obsession" at first, BibleHoarder, because from the earliest days of the Church of England's liberty until after the Restoration in 1660, almost all Anglican bishops were much more closely allied to, and supportive of, continental presbyterians (Huguenots, Swiss Calvinists, Dutch Reformed) than to episcopalians in Scandinavia. This was partly a matter of geography and accessibility, but it did change markedly after 1660. Bishop John Cosin of Durham was entirely in favour of table fellowship & communion with the continental presbyterians, even after the Puritans so roundly destroyed England during the Civil War, Commonwealth, and Protectorate. Many became hostile to the whole polity because of the war, though, which is somewhat understandable. Today the Anglican Church of Canada is in communion with the Evangelical Lutheran Church in Canada, much like the Church of England forms the Porvoo Communion with continental Lutherans. I believe two recent-ish events have caused the "obsession" with - or at least high interest in - the Lutherans: 1. The Papal Encyclical Apostolicae Curae (1896) of Leo XIII, which attacked Anglican orders as invalid. Despite a rigorous rebuttal by the then-Arcbishop of Canterbury Frederick Temple (Saepius officio, 1897), some high-church ritualists in the 1920s panicked and sought ordination via the "Dutch Touch" of Old Catholics in the Netherlands and some episcopal Lutherans as well. 2. Ecumenism of the 1960s has changed many old relationships, and redefined ideas of communion.
If memory serves, the Finnish and Estonian bishops do not have apostolic succession, whereas the Danish, Swedish and Norwegian bishops in theory do (unless we use the model of succession of St. Cyprian of Carthage instead of St. Augustine).
I suspect because of the similarities, in liturgy, and to a certain extent culture (both religious culture, and securlar culture) and Scandanavian influence in early British History (those raiding Vikings who settled in Ireland, controlled much of the north of England/Scotland) See attatched article. Interesting perspective on Lutheranism, i.e. ...it's not actually Protestant. https://web.archive.org/web/20060430170834/orthodoxlutheran.fws1.com/notprot.html
There have been many conclusions of consensus that the Lutheran-Catholic Dialogue agreed-on goal of reunion under the authority of the Pope. Differences are no longer viewed as an impediment to unity. As Cardinal, Pope Benedict communed Brother Roger [Taize] as did John Paul. "210. Thus, Lutherans and Catholics are able jointly to conclude, »Therefore regarding Scripture and tradition, Lutherans and Catholics are in such an extensive agreement that their different emphases do not of them76 Chapter IV selves require maintaining the present division of the churches. In this area, there is unity in reconciled diversity« (ApC 448).82" http://www.vatican.va/roman_curia/p...doc_2013_dal-conflitto-alla-comunione_en.html "This is also, if we’re being legalists about it, correct. The pope has not explicitly given permission to Lutherans to receive Communion. But — and this is a supersized “but” — he’s not telling them not to, either. In fact, he’s insinuating that it’s up to them. The final three sentences give the implicit permission to do just that:" https://onepeterfive.com/good-parents-say-no-pope-francis-on-lutherans-and-the-eucharist/ Ecumenical progress came to a halt when Anglicans and Lutherans began ordaining women [also gay priests].