I dont know man. Obotrites and Rani were probably culturaly and religiously as close as one can be yet they had pretty nasty wars between each other. One of Rani leaders even made alliance with Holy Roman Emperor during war with Obotrites. Regardless culture of Slavs was constantly changing. Some like my ancestors had Romance and Germanic influence once they settled those lands. Russians had Finnic and other influences, etc. In my opinion there would be differences in any case. We Slavs absorbed foregin tribes and adopted certain elements of their cultures.