What I'm looking for is plausible variations of Prince Electors arising during the Hohenstaufen-Welf(-Pope) conflicts.
The Imperial Electors derive from those of the German Electors, those electing the King of the East Franks / Germans. These were the leaders (Dukes) of the "German Nations" - Franks, Saxons, Swabians, Bavarians - also called the Stem Duchies, and the premier, probably 3, Archbishops.
The inheritance of Burgundy and conquest of Italy creating the later named Holy Roman Empire meant the German Electors tended to elect the Emperor and his heir/successor.
The fragmentation of the Stem Duchies altered the secular Electors:
Franconia -> Count Palatine of the Rhine - as premier noble of Franconia.
Swabia -> Margrave of Brandenburg - probably through Welf support then switched to Hohenstaufen
Saxony -> (lesser/younger) Dukes of Saxony
Bavaria -> Dukes of Bavaria - later passed to Kings of Bohemia when the Dukes inherited the Rhine Palatinate.
The Archbishop of Mainz was a permanent Elector by Frederick II, as was Trier I believe. Cologne seems to have been a Welf supporter, Aquileia seems to have been a Hohenstaufen supporter, but I'm not sure when before the Golden Bull that Cologne became permanent.
So, what plausible variations can we come up with. Can we get parity on secular and spiritual where the Empire is divided into Electorates containing one of each?
Etc etc