Yeah okay so this extends to far more than just Nation with the way he's written it and I'm going to take out an excerpt to demonstrate that.
The initial and most glaring problem of narrative based Nation RP's is that each player exists completely at the whims or favoritism of the GM, or Game Master. Were he a childhood friend, a legitimate argument could be made that events that pertain to your nation or civilization have a tinge of preference to them. Or worse, were you so unfortunate to have a bad experience with the GM, you may find yourself treated unfairly by the curator of the game--or excluded from joining entirely. This sets the stage for an unequal start, which is not gamebreaking in and of itself--as nations do not begin their worldly journey from the same positions in the real world, or most fictional worlds--but rather gamebreaking in the sense that not every one is given the fair shake. A GM whose ideals are based on his own opinions and considerations, cannot, based on the purview of the human condition, give every nation a fair shake, as it were.
The second failure of narrative based RP's is the over dependence on a continued narrative cohesion. Battles are often decided by gentleman's agreement between the participating players. The very premise of this idea is nonsensical and removes the incentive to succeed in lieu of a "functioning narrative." In a narrative based Nation RP--in the equation of deciding battles--you are asking someone to intentionally lose in the interest of story. This forced collectivization can cause resentment or even a tug of war of narrative favoritism in the vein of: "I lost last time, you should lose this time." Mechanic based RP's are black and white, assuming they are designed competently, and the functional requirements implemented are strategy and many other times luck (usually via online die roll or through the assistance of Random.org).
It's the Yu-Gi-Oh! problem. No, really.
To those who know me, they know I'm more than a little obsessed with the franchise and can dig up any old YGO RP from any random place (often to my own detriment because sturgeon's law applies) and what you describe here as why only game systems work is the exact
problem I have with most of them. Like, let's think about this for a second.
First, you argue that you're a the whims of the GM and that's bad. To that I say: yeah, no shit. This happens even in D&D campaigns that rule lawyer the shit out of everything. Even if you look at RPing purely as a game, it's still a game you need people for. Not all people are equal. Some people like each-other, others don't. If your group doesn't mesh, no amount of rules is going to fix it. When I get 4 really bad teammates in League of Legends I don't care if I go to win the game when all they've done is berate and heckle me the entire time I was playing. In that same vein, if a GM thinks you're a sub-par writer or doesn't like you personally, no amount of dicerolls are going to save you from being booted. It's the nature of the beast. Par for the course- it's completely illogical to imply that GM bias somehow leaves people on an uneven playing field. Just... look for a different GM? There always needs to be someone overseeing the game, otherwise you just get a chaotic mess. And yes, the guy overseeing it will have biases. If you don't like it, do the job better yourself.
Second, you say that a "gentleman's agreement" is somehow a failure because it will lead to mob mentality, which, afraid as I might be to say it, is kind of a leap in logic. This is where the Yugioh problem comes in. YGO RP's are, obviously, based around a real game, which in turn has a show around it that most RPs draw inspiration from. It ends up causing a lot of problems because nobody can ever figure out how to best structure this. Do we use simulators? RNG our hands? What's the banlist, which cards are allowed? Do we just freeform it? It's a problem every YGO RP faces and, more often than not, those who stick to the real game often become a royal mess. I tried a system like this once, where people RNG their hands. It was a bitchfest. People were petty as all heck when they lost and tried to surrender before even seeing it all the way through, because actually playing the game, as it turns out, creates a lot of salt when people get competetive. This almost ruined the narrative, though I decided to axe it regardless as it wasn't very fun.
My preferred method now
is to use a gentleman's agreement, because actually
communicating with your players ends up causing the least drama overall, since people know what to expect and what they want. If people are still petty and want to win everything, well, I'll just say they weren't even remotely looking for a narrative to begin with. This isn't a failure, it's a complete incompatibility in priority. By actually forcing people to talk it out you create a more cohesive storyline and can give everyone a fair shot in regard to what you both think is best- and if you really can't get over it, flip a coin. It's the same as what I see reflected here- your thesis is that a narrative Nation RP can never work because Nation is more suited to be a game. It's completely asinine if you ask me. Why should losing be a punishment? Losing is a form of growth. Learning from mistakes not only makes characters stronger, but also nations. Taking severe casualties and being in dire straits sounds like a fun position to be in, because now you have to write as in going on the offensive and possibly getting the biggest upset possible.
People looking for a story are going to build a story, come what may. It might take more time than a stats game, because a stats game is a lot easier to figure out, but with enough dedication anything is possible. Insinuating that stats are superior to people talking it out is ludicrous because it's two whole different notions of fun. Stats can die out just as well if the game just, well, sucks.
Of course I'm coming from the perspective of someone who doesn't RP in Nation, but I see the argument reflected into a phenomenon I am all too familiar with, so I thought I'd share regardless. It's just unfair to say something is doomed to fail if you don't intend on giving it a fair shake.