Shogun 2: Total War is unique when it comes to using different units in your army. It depend on how you want to approach the game and next thing you know is the use of different units available to you will be different. It would be important the best and the worst of each, if you want to take advantage of any opportunity your enemy may give you in the battle.
I understand there is a brief description of each of these units in encyclopedia of the game but you will find much more than that in this guide.
How to Use Cavalry Units in Combat
You can use cavalry to flank the enemy and take out their general or missiles or harass the enemy to break their lines and send their infantry in your pursuit. Bow Cavalry are good when it comes to Flanking.
You can kill the enemy units in straight charge. Cavalry charges are effective against Yari Cavalry but they are wary of melee attacks.
If the conditions force you against melee combat in charge, use Katana Cavalry which isn’t the best cavalry unit for charge but, can survive longer and do a lot of damage.
While charging with Cavalry, keep a good look at Spearmen and Missiles. Both can do a lot damage since horses are a big target and they can take them out from distance.
Charge Straight Into Enemy Front Lines
You should only use this strategy in desperate of times, 50-50% chances of it working in your favor. Basically you take your cavalry and charge straight into the enemy front lines. They will take a lot of damage and cause a lot of damage too. You may loose your whole cavalry in the process.
Charge, Pull Back, Charge Again
You can use this strategy effectively as it will keep your enemy’s focus on defense while you plan an offensive attack from sides. You can use Yari Cavalry to its best in this type of attack.
How to Use Infantry Units in Combat
Attack and Defense Lines
Defensive infantry lines provide cover for your missile units and can hold enemy melee units while you do your flanking.
Flank Or Rear Charge
You can use your infantry unit to circle around your line and charge any enemy engaged in combat from behind. It will severely damage its morale and cause a lot of damage.
You can use your infantry units to guard Siege Units. They are also good against Cavalry charges so another reason for you to keep some of these back to protect your precious units or to provide a defensive line against enemy charges.
How to Use Archers in Combat
Put your archers with skirmish mode on in front of your infantry. Now, they will open fire at enemy and move back behind the infantry when the enemy comes in to attack. You can also use Flaming and Whistling Arrows which cause morale damage to enemy units.
Archers are devastating in Siege Defense so make the best of it.
Get your archers in loose formation to win almost all the one-on-one Duels.
You can bring down buildings and clear the enemy castles of melee units using the Siege Attack.
How to Use Matchlocks in Combat
Disable fire at will and put these units in Skirmish mode. Put them on the high ground to make the best use of these units. Matchlocks are devastating against morale and can send an Ashigaru unit fleeing before it even reaches them.
These units are best in Siege Defense. Destroying units even before they reach the walls and that done quicker due to the morale damage.
Flank and Shoot
Move your Matchlocks behind the enemy engaged in combat and get them to shoot them in the back.
How to Use Siege Units in Combat
Snipe The General
You can take out enemy general early in the game with Cannons. More like sniping in the game.
You can destroy the enemy defenses using Siege Attack of your Siege Units. You can get your Siege Units to come within enemy range and provided enough protection, and do massive damage by shooting them from there.
Make it Rain
You can heavily damage enemy units in clusters with an artillery unit.
Make The Best Out Of These Units in Shogun 2
Basically Peasants with spears, low skill, but very useful when it comes to stopping charges. They ability called Spear Wall comes in handy to stop the charging enemies.
Basically Peasants with bows. When compared to Bow Samurai they come in cheap which means more bodies but slower, less accurate fire.
They can defend using their defense screens but won’t be able to stop archers. Still may be useful against matchlock units and force a charge to break up and go around.
Downside comes in you having to place each unit to create an accurate defense screen since units aren’t spaced well automatically which may lead to loopholes in defense.
Similar to Bow Ashigaru, but more accurate and faster rate of fire with better melee skills. They can defeat Yari Ashigaru in melee or hold their ground against Yari Samurai. Their fire arrows are much worth it, but still If you want them to survive longer don’t use them in charge.
Anty cavalry unit without a spear wall. You can use their Rapid Advance ability when you need to take a position held by an unreliable
unit when your general can’t rally or to hold a gate taken by Kisho ninja under stealth.
Effective melee warriors, but may not be very effective when used in charge.
More effective melee warriors, get them in close range to the enemy, give them direction and watch them do the damage. There are only few units that can stand up against Katana Samurai.
These warriors can do maximum damage in minimum time. Their Banzai ability when used just before charging pulls this off nicely. Though, if you are to use No-Dachi Samurai just be wary of archers, since they have almost no armor. It depends on how well you use this type of units, if you use them well you will be rewarded heavily, if you use them poorly, they would be useless at best.
Fire Bomb Throwers
Use them to damage castle walls or use them to blow gates open. They can also be used to break an infantry charge and cause heavy damage to the enemy in process. Don’t let them fire at will and pull them back after the bombing or they will be damage allies in the process.
You don’t even need to throw these accurately, they cause morale loss to enemy anyway. But, that comes at a slow movement and limited ammo. If they hit the unit, you can be looking at between 3-4 to losses to 30-40 depending on where hit.
Longer reach then archers and are more mobile.
Cross Katana Samurai and Firebomb Throwers. You can use them in ambush or you their stealth ability to capture a gate. Their Stealth ability last for like 10 seconds in which they are completely invisible.
Weak armor with better melee skills. Surprise them with some arrows.
Best used to flank or in the charge. Charge, hold, and charge again is the formula you need to follow.
Charge and hold but avoid Yari infantry. Can annilate archers and hammer Samurai infantry engaged in melee combat.
Archers with increased mobility but come expensive.
If you have something interesting to say, just go ahead and comment, I will appreciate any feedback.