I started with that summary of the economic model and how well it maps onto reality, in order to make two main arguments.
The first is that the model needs some balancing. The discussion revealed that the smaller the country, the more likely the human player diverges from the realistic performance of that economy, because of the "free construction capacity" abstraction.
On a sidenote, for bigger countries, the human player is likely to diverge from the realistic performance of that economy for other gamey reasons, the chief of which is that she or he can create a political and legal setup for the country ingame, which is difficult to imagine happening in real life. Things like Free Trade + Laissez-faire in any large country besides Britain, or colonizing in the "right" states, various exploits, you get the idea. We could wave this away as "easily fixable through house rules by the player". I'd be ok with that, if the game hinted at the uninformed player what this country's general play style ought to be. So, more historical flavour content would be appreciated, as usual.
The second argument I wanted to make is that Victoria 3 can't be a complete game about the Victorian Era, not in the way in which Europa Universalis 4 is a complete game about the transition to modernity, unless Victoria 3 provides the player with the mechanics, and the narrative content, to let him discover the story of this transition.
To take again on the theme about the disparity between actors being the defining feature of the Victorian Era, let's see how it's reflected in the development of their societies around the time the game starts.
Of course, providing even a bird's eye view of each of the world's major poilities' institutional and social development in the first third of the 19th century is a task way above my qualifications as a one-time student of history. The best I can do is attempt to make a typology, and sketch a rough order of tiers of development, while enumerating some of the countries which would fall into each tier. We already have tiers of countries in the game (big thumbs up for bringing this Victoria games feature back), so I guess I'm going in the right direction, although I'm classifying here based on different metrics.
So, here goes a huge exposition, most of it you probably are aware of, with some of it you will likely disagree. Take it as a general description of the "measuring stick" I'm using when evaluating how good a job Victoria 3 is doing at portraying the historical period.
First in my rough typology would be the countries at the leading edge of institutional development. Great Britain, the United States, The Netherlands, France. Countries which, to a varying degree, had solved, or in the case of France, had gone to a significant length towards solving, the big question of citizen rights and setting up the "social contract", so that both the government and the governed population were content in their positions. In these countries, the political order of the day, the "agenda", was revolving roughly around questions such as abolition, and/or widening the franchise, and/or securing the rights of workers.
All of these questions were a luxury subject, fit for salon discussions, or debates in literary societies, or universities, but in any case out of reach of the agendas for the next tier of countries. Those were the European countries which, to a varying extent were still living in the shadow of the French Revolution and post-Bonapart era. All those places where the Revolution had lefts its mark on the elites, and to some degree on the masses, but where the elites were now trying to continue as if the Revolution and Bonapartist "import of revolution" hadn't happened. Prussia, Austria, the wider German-speaking space, Spain, and the Italian space. Those were the countries where parts of society wanted to see their own societies catch up to the advances of those in tier one, against the opposition of the elites, or against that of other states.
On the edge of this tier, but in my opinion still outside of it, was Russia. Russia's "political society" was too thin a slice of its pie chart for the country to merit being included in the second tier. It certainly existed, but it took two decades and a major setback in world affairs to push it towards societal reform, and even then, it was reform imposed from above. So, let's just leave it at "Russia is its own thing" for now.
Russia, however, I'd also place in another "club", together with the aforementioned Prussia and Austria. That club is the tier of countries which carried the ethos of being the victors over the Revolution, the major non-liberal powers of the Congress of Vienna. They are the ones most interested in preserving the status quo specifically in terms of spheres of influence and in terms of borders within Europe. Prussia would soon switch towards attempts to alter the status quo, but we are not discussing this yet. Another unifying trait for these countries is the existence of large groups of society which would soon begin acting on their own aspirations for achieving nationhood - Poles, Hungarians, Italians, etc. So that's tier three which partially overlaps with tier two.
Then come the countries in tier four, which I'd define as countries tangentially touched by the Revolution, where the elites are coping with its consequences, but where the massess are largely unaffected by Revolutionary ideas. Here I would put Egypt, the Ottoman Empire, and once again, Russia. On the agenda of the countries of this tier are the attempts of part of the elites to modernize, against the opposition of another part of the elites, but with the massess being on the whole voiceless and uninterested in the conflict. That's a major difference from the countries in the second and third tier. I simply don't see how this fits into the current mechanics.
Latin America occupies the next tier all on its own. Due to a host of factors, the chief of which was Spain's weakness and the inability or lack of desire of other powers to become involved in this region, I'd classify it as a geopolitical quiet corner and a microcosm which was mostly left out of the bigger discourse and where the post-colonial elites took on thier own path to resolve the problems of their own agendas.
Finally, tier six is everyone else. The remainder of the world which was either under colonial rule, or would be the object of attempts to be subjected to colonial rule. Here the agendas are much more local, much more singularly defined by the elites, with much less significance of the masses. The only two states that stand out are China, where formal independence is preserved by its sheer size and scale, and Japan, where the elites pushed the process of modernization instead of waiting to see "what would happen" otherwise. The political agenda here is again one of how to guide the transition, but this time from a much worse starting position than that of the countries in the fourth tier.
So, after all that, I think it's explained why I chose disparity as a leitmotif of the age.
Where is Victoria 3? As far as my expectations go, Victoria 3 hasn't scratched the surface of the task of presenting the socio-political side of the Victorian Era to its audience. It has been three rough years of unfortunate systems being ripped out and rewritten just to get the basic game loop of buildings and markets going in a satisfactory level of the depth of the simulation.
Just based on the quick geopolitical rundown that I gave above, you would expect countries occupying different tiers to present very different sets of problems for the player to solve. Yet in my opinion at least, this is very much not the case in Victoria 3, rather it's the opposite. Countries from very different socio-political contexts play surprisingly, and disappointingly, the same as one another.
The mechanics modelling the political processes seem to be intended to fit countries mainly of the first and second tier, with the rest of the world feeling unconvincingly forced into a "Procrustes' bed" of the Interest Groups-Parties-Clout-Laws set of mechanics.
Before someone objects - yes, I get it, these mechanics are meant to represent various country-specific institutions in a more abstract way. The "Laws" would have been better named "legal framework" because they are themselves very abstracted as well.
These are my subjective impressions, but what I can't shake off, as a player, is that at the end of the day, there are one-size-fits-all solutions and setups, i.e. "states" of these mechanics. The representation is so abstract that the country's peculiarities are not discernable, and societal issues seem to be dealt with in the same way. The player finds a way to empower the IG with the "right" legislative agenda, set up his legal framework and then forgets about the whole system.
Such has been my experience with Germany, Russia, France, Sweden. And when it comes to the input of the country's society, political elite, "zeitgeist", it feels as if this one-third of the game has not been implemented beyond proof-of-concept level.
To these problems we need to add the Technologies tree. Some of the technologies there represent discoveries in various scientific fields, whereas others represent societal institutions which took decades to develop their own vartiants in this or that society. In the game it takes a few years to catch up to revolutionary thought as, say, China.
I have much fewer solutions to suggest here than I have problems to point out. I think the direction to explore in terms of mechanics changes is the toggling of certain mechanics with relation to the country tier and legal framework (form of government, taxes, economic system, etc) as well as established institutions. Same as Laissez-faire disables nationalization and takes away from the government construction, the presense or absense of other "laws" could enable some diplomatic- or government-lens options and disable others. If I was designing the game, I'd lay into these lmitations to make different countries more unique to play.
Then I'd take the plunge and just begin developing a lot of country-specific flavor content and mechanics centered around specific historical situations or types of recurring situations throughout the period. Things on the scale of the Tanzimat reforms or the French July Monarchy, or the Great Game, are what I have in mind, but with more branching, more specific win conditions, and more end states.