The move Paradox made towards splitting the insane superkingdom of Rus into two was a right one, but I'm afraid it's not enough. Here's my proposal for further carving up of Rus into 4 Grand Principalities (somewhat historical), replacing vanilla 2. Here's what it would look like:
Basically, this change would make Russia more realistically split into several "warring states", with already existing Kiev and Novgorod being supplemented by two Grand Principalities from North-East Rus, the cradle of modern Russia: Vladimir and Ryazan. Vladimir was a grand principality for longer than Kiev, and Ryazan kept independent political direction for quite some time after the rest of the North-East fell into Moscovian fold. Moscow actually claimed Vladimir's legacy in its supremacy over the region, and creating Muscovy as one of the kingdoms would be extremely premature (it was an empty field for half of the CK2 timeline).
I've tested this out, and it works great - 4-5 (plus Lithuania) kingdoms form and indeed compete regularly against each other and Cumans. I strongly recommend everybody trying this out.
Basically, this change would make Russia more realistically split into several "warring states", with already existing Kiev and Novgorod being supplemented by two Grand Principalities from North-East Rus, the cradle of modern Russia: Vladimir and Ryazan. Vladimir was a grand principality for longer than Kiev, and Ryazan kept independent political direction for quite some time after the rest of the North-East fell into Moscovian fold. Moscow actually claimed Vladimir's legacy in its supremacy over the region, and creating Muscovy as one of the kingdoms would be extremely premature (it was an empty field for half of the CK2 timeline).
I've tested this out, and it works great - 4-5 (plus Lithuania) kingdoms form and indeed compete regularly against each other and Cumans. I strongly recommend everybody trying this out.