Army Composition Through Early to Mid Game

In a war, battles play a very influential war on the outcome of the war, whether it being the conquering of provinces, forcing vassalage upon a lesser nation, or defending your motherland against foreign scum. The outcome of a battle is decided by various factors, such as unit combat ability, leader pips, unit pips, discipline, unit fire/shock modifiers, combat width, tactics, morale, and army composition.

A battle has two alternating phases, fire and shock, that each last three days. Using a typical 18th century battle such as the Battle of Camden (War for American Independence) as an example, fire is the phase where both lines of infantry fire at each other (quite orderly in the 18th century as well), and shock shock is the phase where the bayonet and cavalry charge takes place. Another example would be a typical battle in the era of trench warfare, such as the Battle of the Somme (First World War), where the artillery bombardment (eight days!) would occur in the fire phase, and infantry would go over the top of the trench in the shock phase. Each nation's army's casualties during each phase are based upon the factors listed in the introduction.

In the early game, units have much higher shock modifiers and shock pips, making the shock phase much more bloody, horrific, and produce much more casualties than the fire phase during the early game. This makes it possible to categorize the early game from military tech zero to military tech thirteen, when the shock phase is much more important than the fire phase in combat. Thus, it is preferable to have high shock leaders during this phase of the game to capitalize upon this.

Later in the game, the importance turns to the fire phase. After military tech thirteen and up, the unit fire modifiers rise much more quickly than their respective shock modifiers, and a new, revolutionary weapon enters the battlefield: artillery. Not only does artillery have quite high fire modifiers, they can fire from the back combat row-unlike their infantry and cavalry counterparts-producing more casualties during both combat phases, as the back combat row can now actively engage the enemy. Not only this, but artillery contribute their defensive pips to the unit directly in front of them when defending. This importance on the fire combat phase lasts from military tech fourteen to the end of the game. Thus, it is preferable to have a high fire pip leader during this phase to further capitalize on the importance of fire.

In the majority of the early game, only two units are available: infantry and cavalry, with artillery making a late appearance at military tech seven.

Infantry
Infantry are the backbone of your army, they man the front line, soak up the majority of the enemy's attacks, are the front of your motherland, and, most significantly, are the cheapest unit to recruit.

Cavalry
Cavalry, on the other hand, provide mainly attack support, are more expensive than their non-mounted counterparts, and are not necessarily good on the defensive part of a combat phase (Side Note: Although you might be the attacker of the whole battle, each combat phase, fire and shock, alternate between attack and defense. This is where your unit's attack and defense pips are applied to the respective phase). However, cavalry have more pips than infantry, primarily shock pips, and are very effective on the attack. Imagine your hussars charging onto a battle and breaking a hole in the enemy's poor infantry's lines with their horses and sabres! Huzzah! During any point in the whole battle, if the amount of cavalry exceeds your tech group's infantry to cavalry ratio, you will get the insufficient support modifier, significantly reducing your army's combat ability (the western tech group has a maximum of 1,000 infantry per 1,000 cavalry, effectively a ratio of 50%, also, quantity of artillery has nothing to do with this ratio. Certain tech groups such as Steppe Nomad allow for 100% cavalry in your armies, making a very powerful army early-game). This is very likely to happen if you have your infantry to cavalry ratio at your tech group's limit before you engage in a battle, as infantry sustain much higher casualties that cavalry in combat.

Artillery
Artillery first appear in the game at military tech seven, and are quite expensive. Using artillery against a neighbor that doesn't have artillery can produce quite a large difference in combat. Artillery being so expensive does not fare well with small nation's economies, both in terms of recruitment costs and maintenance. If you are playing as a nation with a good economy, it is best to use artillery in combat than just besieging provinces/forts with it.

I keep my infantry to cavalry ratio 2:1, or two infantry units per every unit of cavalry. I personally like to keep 15 stack armies of ten infantry and five cavalry each to minimize attrition, as provincial supply limits in the early game are relatively low. If my nation's economy is doing well, I mix in four or five artillery into each or some of those fifteen stacks.

Suddenly, at military tech fourteen, your wonderful infantry's fire modifier jumps by a huge .5, and almost matches your infantry's respective shock modifier. Here, in this point of your nation's military history, marks the beginning of the mid game of warfare, in which the fire combat phase has become very important. At military tech thirteen, your artillery's fire modifier also increases drastically, making artillery much more potent in battle.

Infantry
As mentioned above, at military tech fourteen, your infantry's fire modifier increases by a large 0.5. This almost levels out your infantry's fire modifier to their shock modifier, making infantry effective in both phases of combat. This can be a huge advantage when attacking a foreign nation that has not reached military tech fourteen, whether it be your other western neighbor still at military tech thirteen of those pagan New World natives so terribly technologically behind.

Cavalry
During the mid to late games, cavalry starts to not become such a decisive part of battle as they do not contribute much to defensive stands and they have virtually no fire modifiers, separating them from the rest of the units. Therefore, it is better to keep cavalry counts low.

Artillery
Not only does their fire modifier increase, artillery can engage the enemy from the back combat row, unlike your infantry or cavalry, making an army with artillery much more effective than an army without (however, artillery only deal 50% damage from the back combat row while sustaining no casualties, but get massacred if placed in the front row, making it much more effective in terms of morale and manpower to have them in the second row by keeping ample amounts of infantry). Artillery also contribute their defensive pips to the units in front of them during defense. At the beginning of a battle phase, all of your artillery is placed in the second row, unless there is insufficient infantry in the front row, causing them to be placed in the first row. This is highly undesirable. Thus, it is important to have infantry as well as artillery.

I like to keep stacks of twenty of ten infantry, four cavalry, and six artillery. It is possible, with adequate infantry quantities, to fill your back row with artillery. This would result in a very efficient army, as the whole back row can engage the enemy in combat Imagine your infantry firing at the enemy's infantry so orderly like they did back in the day. Then, your artillery starts booming and tears holes in the enemy lines, where your cavalry charges in and finishes the enemy (think the Battle of Camden in the Patriot)! Huzzah! This is very important when defending in mountainous terrain, as you most likely to have enough artillery to fill up the second row, and the low combat width of mountainous terrain allows you to defend with a much smaller army than the enemy.

Another army composition ratio used by players is having 1.5 times as much infantry as you do cavalry and keeping .5 times as much cavalry as you have infantry. The final ratio of artillery to infantry to cavalry would be 1 : 1.5 : .75.

I recently made a guide detailing my playthrough with Castile/Spain and what I found out and what worked and didn't work in the playthrough. Check it out here:

https://steamcommunity.com/sharedfiles/filedetails/?id=677215854