The last patch changed the Russian Minor tree to add a few more generic missions, but by doing so also combined the conquest of Russia with the conquest of Ruthenia. I enjoy playing Odoyev and Ryazan as an ally to Muscovy, having them form Russia and having me form Ruthenia. This is also a reasonable early game expansion path to later conquer Russia. With the new tree, you must conquer the major parts of Russia before even getting claims on Ruthenia. It feels like making the choice of becoming Ruthenian feel less necessary since at that point you might as well form Russia, which is a much better country.