I have not played much more Victoria 3 since I last talked about it, I just don't find it to be that interesting probably because of how bad the warfare and strategy part of the game is.

To build armies up in this game what you do is build barracks, each barrack will create one Battalion. Barracks in this game function similarly to how factories or farms or any other building does, how these work is that you set a production method, that will require certain inputs and in return produce a certain amount of output, you can also tell some buildings what outputs to priorities. An example is on the far right here.
So improving your army follows the same method that you would use to improve a factory. You research a method of production(type of soldier) and set the barracks to that, so here you see I have the menu for infantry open.
The inputs are the same, small arms are always small arms, you don't ever make better small arms, artillery is the same, you don't ever make better artillery. In fact if you research better artillery(such as breech-loaders) all that does is change the ratio of small arms to artillery that an arms factory produces.
Each nation gets the same soldiers and artillery and everything, there is no way to buff or modify any of this other than to produce a a more advance soldier which every nation has access to. It's not very engaging at all, what I like about HoI IV is the interplay between technology, raw materials and industry that then impacts the army and the the choices that the player has to use this and change this to suit his goals. You don;t get any of this in Victoria 3, you don't even get the ability to control your army.

War and strategy are also bad. When you start a war in this game what happens is that everybody in the area or who has put an interest in the area(and these areas are quite large) will be given the option of taking part in the war and you as a player as well as the AI will be able to choose to sway a country to your cause to join you. This makes wars quite random, I'll play as an African state and start a war with another African state only to have Denmark and some other random African states intervene, I'll load an old save to start the war again and see what happens and this time it's a bunch of other random states intervening, do it again and this time no states intervene at all. There is no reasoning behind any of this so starting any war is a gamble and there is no way to really plan for it, you have no idea who is going to get involved.

Not only that but they will send their entire army to fight in that war, Denmark send their entire army to fight in a war defending some random African state form another random African state. You cannot stop them sending those troops either, it happens during the build up to the war.

The wars themselves are pretty boring, you have no control over it. Each region has a HQ, each barracks you build in that region gives a battalion to the pool of that region and then you set a general to control it. Once in a war you then tell that general what front to fight on and whether he should attack or defend. That's it.

I think I know what they are trying to do with this game, they don't want you fighting many wars, they want you growing GDP and enacting social reforms(most of the loading screens involve protests or revolutions with an unrealistic number of blacks for some reason, there is woman suffrage march and half the women are black) but I just don't find that to be engaging unless I have some ability to do something with it, again, like in HoI IV.