How does eu4 manage the army?

Europa universalis 4 manages the army in the following ways:

In Europa universalis 4, in order to effectively manage the army, we must first understand that the maximum number of troops in each country is affected by basic national strength, national wealth, scientific and technological level and other factors. When recruiting and maintaining the army, it is necessary to plan money and human resources reasonably to avoid waste. Make a good recruitment plan in advance to avoid the failure of the war because of too long time, and plan the mobilization plan reasonably to save time and labor costs.