It's a shame your team isn't considering the Orthodox option (not sure about the Teuton option?), as it actually was taken in consideration at the time by Jogaila.
His Russian mother, daughter of Aleksandr Mikhailovich of Tver was convincing him to marry the daughter of Dmitry Donskoy of Moscow/Vladimir. It was a worse option, because it made Lithuania to become a subject and barely helped with the Teuton Knights problem, but an option nonetheless, one of the upsides being the appeasement of the local Orthodox population.
Being converted by the Teutons themselves was also humiliating but, if push comes to shove and a deal with Poland or Moscow isn't brokered, what is stopping such a development?