There is a modern re-interpretation in Finland of Luther's writings. Some Finnish Lutheran theologians, led by Mannerma and influenced by discussions with the Russian Orthodox Church, have asserted that much of Luther's teachings are much closer to Orthodoxy that is commonly thought.
So, if you assume this interpretation is correct or allow some theologians in Scandinavia to construct it much earlier, you can achieve your goal. Adding in better relations with Russia and stronger overtures from Luther and Melanchthon to Jeremias II would help.