The story's more interesting if he doesn't get stopped, and somehow succeeds and continues to succeed. These are stories we are telling after all, not simulations of probability.
I'll reiterate an earlier question I had. How exactly would he be stopped? He's now the single Evil member of a community who knows about Evil, but is 100% unaldutered Good. He can't be reformed by force, because Good in the OP are forbidden to oppress, maim, and kill. So he goes around, teaching people that instead of accepting to die from hunger, they should take up arms and go plunder the rich orcish tribe who had a surplus this year (but they are Neutral, so they didn't care about their Good neighbour enough to help them from the famine, they preferred to stockpile for their own future use). After all, they are orcs, not the same species as them, so it's not as if they shouuld care. People recognize it's an Evil teaching. Many of them, having just lost lots of family members and being told by the authorities that their death was the optimal result since the one that weren't fed were selected according to Good principles, adhere to his political party who professes to keep everything as is, except that in time of dire need, it's OK to attack the orcs. He spends his time convincing people that the famine was caused by the orcs, convincing them progressively that the orcs are a threat. At first, only 0.1% of people accept his teachings, but he slowly gathers more and more as people are struck by various natural disaster that the orcs should be forced to be Good and share their wealth in time of need instead of being allowed to be Neutral, saying that Neutrality is the gateway to Evil, in order to make his teachings more acceptable to a majority. Then he converts 1%. How exactly does Good stop him? By shooting him in the head? By putting him in jail? By sending him into reeducation camp? Those methods doesn't reeks of Goodness to me. Good is simply impotent to prevent his rise. Also, he can't be fined because he has nothing (and why would anyone accumulate capital when society provides for his needs anyway?)
At some point, two or three generations later, he or one his scions gets elected president and the Good country creates an army to wage war on the orcs. Evil has won because in the scenario posited by the OP (Good doesn't force people), a total victory of Good of the magnitude you're discussing mean society would recognize the problem of a resurgence of Evil, but not be able to stop it.
If people in the settings are free to follow whatever ideology they want, because Good isn't brainwashing into being Good, it's I think convincing that such a scenario could happen. In real life, it happened with parties openly calling for the extermination, on principles, of other humans. Here in this scenario, the proposal the Evil Guy makes is much milder: he proposes to attack another species (in real life, we're making species extinct because they taste good, or just because they don't look nice for a majority of us to care -- like the species of insects that get extinct because we destroy their biome but aren't protected because they aren't as cute as baby seals), and he proposes that "only in time of extreme need, when our brothers and sisters, who are Good, are in a dire situation -- and I remind you all that the orcs are Neutrals, not Good! Can we stand doing nothing and see them feasting while our children are dying from hunger?".
A Muscular Neutral group would naturally oppose Good in that they wouldn't want a total victory of Good that would lead a society to renounce coercitive measures, including Evil measures, because after that they would be very susceptible to any kind of resurgence of Evil. There is no need for the resurgence of Evil to be a high probability. It only needs to be realistic enough so the Muscular Neutral group feel justified into action to prevent Good from losing its teeth by excessive Goodness.