Government is more a feedback loop, I saw enough examples as bad government can corrode whole society and opposite can happen too. Look on current USA, this can go in any way, one person making one correct decision could define next 100 years of it. No society is unified, all have some subgroups, and depending on circumstances everything could go upside down.
But government still needs a strong and integrated nation to regenerate itself reliably over time. Russia had several revolutions, but each time it moved to the same core, surviving both the complete change of its elites in 1917 and the total economic collapse of the USSR. No matter the Tsar or Stalin, Russia will remain Russia. Just like if you turn the planet Earth into dust, that dust will accrete back to create the planet (although likely very damaged), unless it gets velocities larger enough to escape the synergistic gravitation of all other dust particles. On the contrary, Roman Empire got disintegrated, and its language went extinct. So government is more of the function of what there is under it.
If you're a single person on an uninhabited island, then you're both the king and the people there, but surprisingly not much you can do. I.e. if Bill Gates gets onto an uninhabited island, he wont create Microsoft. If he gets on an island with some uneducated aborigines, there wont be a Microsoft either. To create Microsoft, Bill Gates needs a large, healthy and educated nation with a lot of resources and developed technologies. I.e. Bill Gates is the function of the nation, which itself is a function of the environment it has, which is, well, first of all shaped by that force called gravity.
Anyway I still keep thinking about the proper way to implement leaders/officers in the game, what makes people loyal and breaks loyalty. I.e. why for example Putin's officers wont just kill him, and wont start a war between each other. What truly stops these generals? How does the loyalty arise?
In addition there is a question about how to make AI challenging. There are a few possibilities.
1. Non-cheating AI. That AI just doesn't cheat and start with the same resources as player. Hard to implement and not very exciting.
2. Rubber band AI. Cheats by having its income to be a multiple of player's income. So the more money player makes, the more money the AI makes. Such AI will always be on match with the player, no matter how quickly player acts to capture resources. The AI will be annoying, since no matter what player does, it will still come back, and will be treading on the tail. The game will likely turn into some strange meta, where player will try acting with low income to avoid turning AI into powerful opponent. Player basically plays against itself.
3. AI gets stronger with time to the point of being impossible to beat (original XCOM AI). Such AI will pose ominous challenge for inexperience players, yet will be boring for advanced players, who can managed to get far ahead of time. And the speed with which AI gets stronger is something hard to balance. It quickly gets from easy to impossible. I.e. that is just a game with a time limit, where player can move time back with bonuses. Original Civilization also had similar AI, varying its speed with difficulty, but modern remake uses a non-cheating AI, which can still beat novice players:
https://techcrunch.com/2016/12/06/aragos-ai-can-now-beat-some-human-players-at-complex-civ-strategy-games/4. Stupid AI. Starts with a lot of resources, but doesn't care to use them, instead attacking player with small manageable forces. Typical for most video games. I.e. if all monsters on the Doom map will suddenly go after the player, there will be no chance to survive. But monsters are too stupid to cooperate, so player can kill them one by one. Sad story. Later games like Quake Team Arena tried to make non-cheating bots, which were far less exciting than bullying the clueless Doom monsters.
5. Trigger-based AI. The AI reacts to player actions with unpredictable cheating, possibly random. I.e. if player moves near AI city, the otherwise docile AI will respond with full force of dishonestly earned resources. Pioneered in Doom games, with trigger sectors, unleashing monsters.
Ideally single player AI should react to player's advances and try to disturb them. So I will likely go with a trigger based AI influenced by the difficulty level and random dice roll. Such AI can have almost unlimited resources and act unpredictable, or according to some narrative. Although I still plan to bind AI resources to the actual income, just provide with larger starting resources. I.e. no gold will be materialized out of nothing.