This may be a controversial take, but here goes...
I've consistently supported limiting the alt-history focus tree paths for several nations (e.g. no communist path for Japan, no fascist or non-aligned path for the Soviet Union, no fascist path for most democratic countries, etc.), but every time I do, I get replies saying how that would remove all the fun of alt-history paths, and when I respond by saying that alt-history should be limited to only plausible historical contexts I get backlash on that. It seems that Paradox agree with these people, because they consistently keep putting in alt-history paths even when they make absolutely no sense - it's ridiculous that Japan has a communist path but Germany - the country that actually had a communist uprising 18 years before the game's start date and had multiple socialist and communist political parties - doesn't. Japan was historically one of the most violently and ideologically opposed countries in the world to communism, especially by the time the game starts where the country was run by a quasi-fascist military dictatorship.
Frankly, if it were up to me, I'd be pretty strict on limiting alt-history, and instead put all the devs' time and effort into massively fleshing out the current ideology/politics of each nation rather than making four smaller and less detailed paths. I'd love if each ideology had multiple branches within the one ideology, say for example for democracies you can pursue centrist policies, centre-right policies, far-right policies, centre-left policies, or far-left policies, all without actually having to convert to fascism or communism. Give the player some choice in how they want their country to develop, not just be red, blue, orange or grey.
Countries aren't such monolithic, binary entities in real life where being democratic means they always follow the same socioeconomic policies as every other democracy. Some democracies are considerably more left-wing than others. I mean look at the UK for example - in most of the game's time period it was ruled by the Conservative Party, exemplified by arguably the single most conservative modern British PM, Churchill; but then following his premiership, the Labour Party was voted in by a landslide and their PM, Clement Attlee, was arguably Britain's most progressive and left-wing premier to date, introducing a multitude of socialist policies and completely changing the UK's socioeconomic environment, but all completely within the same democratic framework that had years of conservative rule.
But HoI4 doesn't really let us do anything like that. Instead, you usually only get one type of approach you can pursue with each ideology - the democrats are all progressive, the fascists are all extremely right-wing, the communists are all extremely left-wing, the non-aligned... do whatever the hell they want, I guess. There's almost no room for alternative paths within these historical ideologies. Several mods address this - one of the best being Calm Before the Storm, which adds huge and multi-faceted focus trees for several countries, the best being for the UK, Germany and the USSR. In each of these countries you can choose what type of each ideology you want; whether you want to be a moderate centrist, or lean either right or left, or go full-speed to the extreme of either political stance, but all within each ideology. As Stalin you can choose to continue hardcore oppressive Marxist-Leninism, or choose to gradually soften and liberalise the USSR as eventually happened in the 1950s. Similarly, with Germany, you can be a far-right party and institute many of these policies without being a full-on Nazi, just like you can be a far-left party and introduce many socialist policies without being a communist.
This is how focus trees should be done, in my opinion, not the current approach of "I'm a communist but now I want to be a fascist so ill just click a couple of buttons and completely reshape the social, political and economic landscape of my country overnight lmao".
Anyway.... that's my two cents.
