Third pair in Russia? Yes, keep dreaming. You can say that they could be even first pair in Russia, if a plane carrying all the seniors pairs falls down. But hopefully that's not likely to happen, so Mishina/Mirzoev would have to stay in queue like any other Russian pair team. Look at Tarasova/Morozov, last year at the nationals they were clearly better than Kavaguti/Smirnov, yet they were placed below them. It was lucky that Stolbova/Klimov and Kavaguti/Smirnov withdrew from the Europeans and that Kavaguti/Smirnov withdrew from the worlds, because otherwise Tarasova/Morozov wouldn't have been sent, as a last year's pair number 4. I am not sure why you think that it would be different for Mishina and Mirzoev. Even if Kav/Smir and Volo/Trankov retire after 2018, there still will Stolbova/Klimov, Tarasova/Morozov, Astakhova/Rogonov and Zabijako/Enbert, and M/M would be made to wait until they are significantly better than either of those pairs. It wouldn't be enough to be as good as them, they would have to be much better to be sent to Europeans/Worlds. And it is not even certain that M/M would be number five pair. Boikova/Kozlovskii now managed to beat M/M at the nationals, so the chance is that they could potentially be beating them in the future too. And suddenly you have M/M as Russian pair number six...