help with army recruitment

[Lewis]

put simply, I've been training troops constantly for 12 years into my playthrough as the petty kingdom of mumu (noob ireland start) & low & behold I find myself not knowing what the hell is going on, this game doesn't do the best job of explaining, well, anything! how have I only gone from 800 soldiers at the start of those 12 years to around 900 in 12 years when ive constantly been recruiting? what am I missing? some dude with 1 county just south of me went from 400 troops to 1000 over a couple of years, ive been training troops constantly!?

[Lewis]

https://gyazo.com/ac2075255d589b276bd77ad6ca8351d5

[Lewis]

so the guy to the south of me goes from 400 to 1000 in the time it takes me to go from 800 to 900, recruiting constantly, so confused.

[galadon3]

You don't actually recruit troops that way, the job just increases the levy-size of the province while the marshall does it.

Each of your holdings has a maximum number of levy-troops it can provide, the basic number is determined by the buildings in the holding then you get a number of modifiers to that, the marschal doing that job is one of the modifiers.
Your Martial-Rating has a huge impact too.

When you go to war and your levy has losses it will slowly replenish back to that maximum. You can actually see those two bars under the small picture of the castle.
One is the garrison (never leaves the castle, gets replenished first and is basically what defends it agains sieges) the other one is the levy, if the bar is filled its at its maximum capacity and will only increase further if you either build / upgrade a building that provides levy-troops or one of the modifiers changes for the better.

For a detailed overview of levies:
https://ck2.paradoxwikis.com/Levies

[Lewis]

thank you, I feel stupid.

[al_x_ator2411]

For more personal levy try raising the martial atribute of your ruler (different options depending on DLC) and improve your holdings***.

***Start by building all the economic upgrades (castle walls, castle town) and then move on to cheap military buildings that add a lot of low quality soldiers (militia training ground) and finish with more expensive buildings that add high quality soldiers (stables).

The reason to build in that order is so 1) you don't go bankrupt whenever you raise your levy and 2) because the AI takes numbers and not quality into account when deciding to attack you.

For more vassal levy make your vassals like you more. The bigger you get, the more important this gets.