Ohhhhh, yeah, so since you're not an exchange/Yuletide regular you may not know, but there's a whole Thing around letters and posting letters and gaming for people. There's even a website someone made (https://tagset2019.firebaseapp.com/#/) that collects letters. (Why Yuletide does not just open requests to plain view I do not know. Possibly no one does except the mods.)
And, of course, you're right; it's still gambling (and in your particular case might not work anyway because a lot of people who would be willing to write Fritz/Katte would probably decline to even consider signing up for Suhm). I don't mind the gambling aspect, in large part because I don't apparently think of fic exchanges in terms of relationships :) But your point about being able to request more characters/relationships is well taken! Yuletide is too big for that, I think. But I regularly request literary fandoms where I nominate and/or request zero characters, so...
Re: Exchange structure
And, of course, you're right; it's still gambling (and in your particular case might not work anyway because a lot of people who would be willing to write Fritz/Katte would probably decline to even consider signing up for Suhm). I don't mind the gambling aspect, in large part because I don't apparently think of fic exchanges in terms of relationships :) But your point about being able to request more characters/relationships is well taken! Yuletide is too big for that, I think. But I regularly request literary fandoms where I nominate and/or request zero characters, so...