Claims census 1897 is "fantasy map"
https://en.wikipedia.org/wiki/Russian_Empire_censusRoma, Romania, do you claim Italian is "Romanian dialect"? Muscovy was Rus colony, grew under Golden Horde, renamed in 1721. Rus Grand Prince Володимѣръ Свѧтославичъ — Ukrainian name Володимир (Volodymyr) not Moscow Владимир (Vladimir). Language of Kyiv can't be dialect of its former colonies language.
Slav languages are mutually intelligible. I've checked spoken Slovak, Polish, Croatian, Bulgarian. Do you claim these are "dialects" of Moscow language?
Eneida translated to Polish:
Eneasz rzutkim był młodzianem,
Podobnym całkiem do Kozaków,
Radzącym z każdym złem spotkanym,
Zawziętszym nawet od burłaków.
"50% of this text right off bat"