During the mid game money becomes obscenely plentiful, especially if know you way around trade and production. I don't even know anymore what to spend my money on anymore. The ai also seem to have a similar issue, sometimes you can even get up to 5k by just attacking some random German state. And because of this wars often end up in merc spam, money becomes cheaper than manpower and ai ends up mainly recruiting mercs, defeating armies becomes meaningless even though they often decided the outcome of wars throughout history, I am starting to feel that I am playing total war, in which losing armies hardly hurts you or the ai. Because of this I myself started to use mercs as my main infantry, which allows me to constantly go to war without having to wait for my manpower to replenish. The professionalism buff hardly makes a difference in my opinion, and its easy to raise even with an army of merc infantry.
There is an easy way to fix the merc spam, my suggestion would be to add an international mercenary manpower pool to the game, each faction gets a specific share of this manpool depending on how well they do in battle, mercenaries are renown for switching sides when things turned ugly. So each time you lose a battle, you should also lose a share of the international merc manpower pool, this would make defeating endless stacks of mercs more meaningful.
Sorry in advance for any grammatical errors in my post, I am not a native English speaker.
There is an easy way to fix the merc spam, my suggestion would be to add an international mercenary manpower pool to the game, each faction gets a specific share of this manpool depending on how well they do in battle, mercenaries are renown for switching sides when things turned ugly. So each time you lose a battle, you should also lose a share of the international merc manpower pool, this would make defeating endless stacks of mercs more meaningful.
Sorry in advance for any grammatical errors in my post, I am not a native English speaker.