I still cannot re-read Anderson's Technic History without rethinking its subdivisions. It seemed obvious that the Trader Team sub-series comprised:
"The Trouble Twisters"
"Day of Burning"
However, I now regard Mirkheim not as part of but as a sequel to the series as I will explain below. The Trader Team has three periods. The first starts with "The Trouble Twisters" and ends with Satan's World. Only one work, "Lodestar," is set in the second period and no works are set in the third period which we are told lasts for five years. After the third period, the team disperses and is temporarily reassembled for a different purpose only once three years later in Mirkheim.
In "The Trouble Twisters," Nicholas van Rijn explains his "trade pioneer crew" idea to his protege David Falkayn and Falkayn leads one such crew on its first mission. The reader might expect the remaining installments of the series to recount further missions of this crew but instead we do not see them on such a mission ever again. They are engaged in different kinds of activities in the next two works: a rescue mission in "Day of Burning" and a different kind of investigation in Satan's World. In "Day of Burning," Falkayn states that he has seen planets devastated by nuclear strikes although visits to such planets would not be a usual activity for a pioneer crew.
In Satan's World, their entire civilization is threatened. The team has to be split up and might not survive. Thus, this volume is a potential ending to the series. It ends with the team members rich for life but setting out again as a pioneer crew not because they have to but because they want to. That is why I say it ends their first period.
In "Lodestar," the crew takes a few days off on a pleasant planet, then Falkayn seeks out and finds a source of wealth which he gives to the poorer races, not to the wealthy van Rijn: an end of innocence for the team. The story features van Rijn's granddaughter, Coya. In the third period, which we do not see, Coya has married Falkayn and joined the team. This period ends when the Falkayns start a family and stop pioneering and the team disperses.
In Mirkheim, van Rijn reassembles the original team not to resume pioneering but to address an emergency which is the beginning of the end of the League period. Thus, Mirkheim is a sequel. I now think that omnibus collections of the League period of the Technic History should be:
THE POLESOTECHNIC LEAGUE
LATTER DAYS IN THE LEAGUE
Volume I would comprise seven stories introducing, apart from the League, the Jerusalem Catholic Church, Ythrians, Avalon, Adzel, van Rijn and Falkayn. Volume II is van Rijn. III is the team. IV would be Mirkheim preceded by two other stories set during the League period.