Well, not that the game had to portray it, but from OTL perspective Novgorod was doomed by 1444. Even Novgorodians themselves understood that, the questions were "Moscow or Lithuania?" and "Submit now, or wait for a miracle?". Their main problem was, ironically, their own success: their population far exceed the number that could be fed by their lands, so they heavily depended on food supply from Moscow and Lithuania. By 1444 Moscow already acquired foothold on Beloe lake, so it could even cut the Novgorod's trade with its colonies at will, and unsurprisingly, most of them became a sort of Moscow-Novgorodian condominiums. Add to that the collapse of GH, that resulted in chaos in the Volga region that made Volga trade impossible (and Novgorod greatly profited when GH was strong, because it meant that Volga trade is safe and active), and you can see that republic was on the verge of collapse.
So yeah, Novgorod can become a power in player's hands, but AI usually loses, which is pretty much correct. But then again, I like historical rail-roading, I know most people hate it
Yes, the game had to portray it. Novgorod was pretty much doomed in 1444. A truly historical start is not the same as historical railroading, where losers are artificially gimped so they will lose even if the winners make stupid decisions (France in HOI3).
