“If Novgorod had won (not theoretically possible), then “Russian” history would have been quite different”
Well, when I play Europa Universalis IV I can win with Novgorod. Not easy, but it can be done if you pounce on Muscovy at just the right time, usually when they are tied up fighting someone else. But then Novgorod just becomes Russia, because you are basically forced to expand in the same direction, since you cannot challenge Scandinavia or Poland-Lithuania for a long time, and once you expand that way, you end up having all the same problems and enemies that Russia historically had.
But your political ethos differs as you won’t go down the autocrat route