Well, we knew that this was going to show up, here.
I’m just gonna spitball this, though: have we given some consideration to the idea that, maybe, this entire Jedi/Sith dichotomy isn’t working out as a practical working paradigm? At this point, ‘Jedi’ training consists of whatever Luke remembers of what Yoda and Obi-Wan remembered of their training, and their original training regimen assumed an infrastructure and organization that simply doesn’t exist anymore. For that matter: the original Jedi organization was, to put it cruelly but accurately, a collection of smug, self-centered chowderheads who fell down on the job and took the Republic with it.
And the Sith? The Sith aren’t any better: they’re just several millennia further down the road that the Jedi are walking, when it comes to training up new members. One master, one apprentice, and aren’t the Sith Lords of Korriban weeping in their tombs right now? They used to have a more formalized system, you know. In the old days. Not this cobbled-together monstrosity.
…Rey and Kylo Ren should come to an agreement: stop meddling! Each goes to opposite ends of the galaxy, and swears not to intervene in Galactic events for five hundred years. Let them build up whatever it is that they wish to build. And let the Force stop being used as a tool for generals and politicians.