Star Trek: Discovery - Ups And Downs For Season 3 Episode 4 Forget Me Not

After going from the aberration to the Trill people, Adira suddenly becomes the only hope, Obi-Wan. While there is an argument for the successful joining of a Human host with a Trill Symbiont, this surely can't be the first time that the Trill have discovered this? They state repeatedly that they have had their population decimated by the Burn, which is problematic in itself, yet they've never considered thinking outside the box?

There is much of the history of the future that the audience is yet to discover, which, if this is to continue, is going to reach 'Lost' levels of confusion - but writing in these kind of changes and twists while we are all attempting to find our feet in this new year is becoming highly frustrating. The Trill have never been shown to be as inconsistent as they have been here. Again, while there is an argument for isolationism after their losses, would it not have made sense to attempt joining with another species?