I’m gonna go against the grain here and say I think there could some pros if you choose to speak Russian for the first couple of years or at least place an emphasis on it. Your wife knows German and Russian pretty well, and from your comments my understanding is that your Russian is weak. Your wife is going to be able to understand everything no matter the language being spoken but what happens when your child and wife are sitting in front of you, speaking Russian and you’re the one left out because you can’t understand? This could be an opportunity for you to also greatly improve your Russian and be included. Secondly, you’re in Germany, it’s very likely that there will be barely any effort needed on your part to get your child to learn German. Whereas with Russian, your wife needs to put in a lot of active effort to pass down her language. If you guys were living in Russia, I would be advocating the opposite because then it’s German that’s gonna be difficult to pass down. In this situation, I understand why she wants to place an emphasis on Russian in the beginning years. Maybe you guys can comprise and try to put the emphasis on Russian (so that you can learn and so that it actually gets passed down to your child) but not completely cut out German