I'm really looking forward to this game.
In the dev diaries it says Marx has a chance to show up in your country and lead the socialist interest group when you research Socialism.
Start date is 1836, and from what I gather if you make the right moves you could trigger a revolution fast enough for Marx to see it in his lifetime.
The game's end date is in 1936, so Lenin is likely to be in there too.
For those not familiar with the Victoria series: it's a society simulator. War isn't a focus of the gameplay, but an extension of the political gameplay. It's all about how small changes create big effects.
If you want to make a country communist, for example, you don't click a communism button. You have to create the conditions for it - anger the proletariat but also educate them, let the capitalists run amok, industrialise and create dense population centers, get a charismatic figure like Marx or Lenin to lead the socialist interest group and fire up those population centers... make your military weak (or shape the culture of the military so that they support the revolutionaries)...
It's like gardening. You sow seeds and watch what unfolds.