Land unit selection
This article is focused on selection of land unit types at the brigade level. For a more division-oriented view, see division building.
Due to the Practical Knowledge system, it makes sense to try to concentrate on as few Practical types as possible in order to ensure that your constructions contribute to and benefit from as high a Practical level as possible. Furthermore, concentrating your unit selection will reduce the number of techs you need to keep your units up-to-date. On the other hand, the more types of units you use, the more versatile your army will be. Therefore, when choosing units to research and build, your goal should be maximum versatility with the fewest different types of units.
Infantry Versus Militia
All nations will necessarily need some boots on the ground. Even for nations such as the United States, with potentially enough IC to put every soldier in a tank, the poor performance of armour in bad terrain and amphibious assaults will make it necessary for some soldiers to fight on the ground, whether as Militia, Infantry, or Mobile (which uses many Infantry techs as well). A lot of research is necessary to keep Militia and Infantry up-to-date: 4 repeating techs for the hardware, another 1-2 repeating techs for Doctrines, plus various one-time and prerequisite techs, to say nothing of the effect of Practical knowledge on construction. Therefore, it is generally a good idea to choose one or the other. But which one? Let us consider the features of each:
- Units: Militia, Garrison, Police (generally considered to be useless), Partisan (non-buildable)
- Low officer requirements.
- Very cheap in terms of IC.
- Moderate use of manpower per-unit.
- Very slow.
- Very low initial consumption.
- Upgrades poorly.
- Units: Infantry, Marine, Mountaineer, Paratrooper, Engineer
- Necessary for Mobile (but does not share same Practical)
- Higher officer requirements.
- Cheap in terms of IC.
- High use of manpower per-unit.
- Low initial consumption.
- Upgrades moderately well.
- Benefits from more one-time upgrades (e.g. terrain-specialized equipment).
Clearly, Infantry Theory is a far more versatile tech branch, considering its variety of special forces and importance for Mobile units. Infantry Theory units are faster. The Large Formations tech only addresses the frontage component of the Militia's lack of concentration of force; they still suffer from worse stacking penalty from the larger number of brigades needed to produce the same force. Considering how weak Militia units are compared to Infantry, their manpower advantage arguably disappears as well. These are a strong argument in favor of Infantry.
What does Militia Theory have left on its side? In early years it has an advantage in consumption; however, since each upgrade increases the consumption by 0.01 supply and fuel per upgrade per unit, the gap closes as the years go on. Although the IC benefit is significant, in general it is manpower, not IC, which forms the final barrier. Even Nationalist China, with its massive manpower and only mediocre IC, will soon be drained of manpower if it focuses on either Militia or Infantry. This leaves officer requirement as the only decisive advantage of Militia Theory.
If one estimates one HQ for every 16 brigades, and two Militia brigades equal one Infantry brigade, then 16 Infantry brigades with one HQ is equal to 32 Militia brigades with two HQs, with 1700 officers for the former and 520 officers for the latter, a savings of just over three-fold.
Armour, of any practical form (i.e., not Super-Heavy), possesses the following salient characteristics:
- Speed. Armour is faster than Infantry; if you skip armour (in the "thick metal plating" sense) upgrades, they are exceedingly so.
- Low softness. This gives a measure of protection against most attacks. More importantly, it is half of the battle of getting the coveted Combined-Arms bonus. Tank Destroyers are the only other "hard" unit.
- High concentration of force. Once Spearhead Doctrine is researched, armour has the same frontage as other combat brigades; their high stats per brigade allow you to focus power.
But, what type of armor to pick? With four hardware techs per type, using more than one is quite expensive in terms of research.
Super-Heavy Armour is clearly not practical. They are not appreciably more powerful than Heavy Armour, yet they are slower and more costly.
- Cheap for armour.
- Extremely fast.
- Shares tech with Motorized and Mechanized.
- Upgrades extremely poorly for armour.
- Moderately expensive for armour.
- Fairly fast.
- Upgrades well.
- Shares tech with Self-Propelled Artillery (normal and Rocket) and Tank Destroyers.
- Expensive for armour.
- Moderately fast.
- Upgrades a little better than Armour.
- Shares one tech with Tank Destroyers.
Light Armour suffers greatly from its poor attack upgrades compared to Armour—therefore, as a combat unit, Armour is preferable to Light Armour, though the latter may serve well as an exploitation unit.
On the industry side, Heavy Armour costs much more than Armour for little extra combat effectiveness, and furthermore, shares fewer techs with other units. Even one-to-one (i.e., ignoring industrial costs), the advantages of Heavy Armour are questionable:
- Heavy Armour has quite a bit more Defensiveness than Armour, but Armour has better Toughness. As armour is on the attack more often than not, this is probably at least favorable to Armour.
- Heavy Armour has lower softness; this may increase durability slightly.
- Heavy Armour has slightly higher Hard Attack per upgrade.
- Armour is much faster. Heavy Armour will have to give up significant numbers of tank armour upgrades in order to be as fast as, say, Engineers.
- Armour suffers smaller terrain penalties across a wide variety of terrain types.
It is probably reasonable to say that Armour is better even one-for-one if one cares about speed, or plans to do lots of fighting in poor terrain, whereas Heavy Armour wins out otherwise. If industry is a constraint, Armour is the clear winner.
An interesting alternative to armour as far as hard units go are Tank Destroyers. It is really the armor upgrades that sap the speed of Tank Destroyers; without these, they are faster than Armour! Without speed, it is probably better to use the much cheaper Anti-Tank, so this is good idea for Tank Destroyers.
While Armour, as a combat brigade, can handle itself on its own, Tank Destroyers are a support brigade with very little Soft Attack. As such, they must be grouped with other brigade types to be effective.
(Conventional) Artillery Versus Rocket Artillery
Rocket Artillery is cheaper, faster, and has better Toughness than regular Artillery.
Artillery consumes less supplies and has better Defensiveness than Rocket Artillery.
Rocket Artillery upgrades better than Artillery; however, since upgrades for Artillery start earlier, Artillery starts with an attack advantage. It takes roughly until the end of the vanilla timeline for Rocket Artillery to catch up.
Rocket Artillery requires three prerequisite techs: two levels of Artillery carriage and the activation tech. After this, upgrades are in 1939, 1940, and every two years afterwards. Starting from scratch, by 1940, 7 techs have been expended.
Normal Artillery requires no prerequisite techs, but upgrades are in 1918, 1932, and every two years afterwards. Starting from scratch, by 1940 12 techs have been expended.
Therefore, in terms of total techs to keep up to date starting from scratch, Rocket Artillery is actually five techs cheaper.
Self-Propelled Artillery requires level 3 Light Armour techs; if you were planning to use Medium Armour without researching any extra Light Armour techs, this requires 4 additional techs. Meanwhile, Self-Propelled Rocket Artillery requires only the Combined Arms Warfare tech, which should be researched anyway.
Techs also increase the IC and time costs of units. Within the game's timespan, you can expect Rocket Artillery to be 20-25% less expensive than regular Artillery.
Both normal and Rocket Artillery use Artillery Practical for both techs and production. However, Artillery uses Artillery Theory, while Rocket Artillery uses Rocket Science. Artillery Theory is also used in AT and AA techs, whereas Rocket Science is also used in rocket techs. Which one is better depends on which tech branch you plan to concentrate more on.
- Marines, Mountaineers and Paratroopers use the same equipment as normal infantry and require only one additional doctrine (Special Forces) for organisation upgrade. This means adding a healthy mix of elite infantry to the army is very easy research-wise.
- Marines used in tropical conditions like jungles of the Indochina highly benefit from Engineers movement bonuses there. Engineers also help dig-in faster after taking enemy port and offset one or two levels of coastal fort during amphibious invasions. Both Marines and Engineers have their Organization improved by one doctrine: Special Forces.
- Mixing Infantry and Tank Destroyers will provide a very costly front unit of infantry with low Softness, Combined Arms bonus and very high Hard Attack. Such a division takes almost a full year to construct but can push back wave after wave of enemy tanks and infantry.
- When you upgrade normal Infantry, you also are upgrading Motorized and Mechanized Infantry. More Mot and Mech upgrades come from Light Armor tree. So when aiming at building a force of L Arm and Inf, it's very easy to supplement it with Mech and Mot since they are upgraded along the way. The downside is having to research multiple doctrines in different trees.
- Schwerpunkt and Blitzkrieg doctrines improve morale and organization of all types of Armor (Light, Medium, Heavy, Super-heavy) and also Armored Cars and Tank Destroyers. This mean they allow to create a Combined Arms division without having to research any of the Superior Firepower doctrines.
- Medium Armor shares Engine, Reliability and armor research with Tank Destroyers and both types of Self-propelled Artillery (Rocket and normal) making it easier to upgrade divisions built using only these units.
- Light Armor shares doctrines and Engine and Reliability upgrades with Armored Car allowing to build cheap and easily upgradable exploitation units based on those two.
- Light Armor, Motorized and Mechanized Infantry share Armor, Engine and Reliability (Mech also shares Gun) upgrades allowing to build a bit stronger variant of Combined Arms exploitation divisions than above example.
- Tank Destroyers heavily benefit from Medium Armor upgrades and also share armor upgrade with Heavy Armor so their usage is advised only when heavier types of tanks are in use.
- Light Armor used in hard conditions like in jungles for exploitation benefits a lot from presence of Engineers in the unit which both improve movement and provide Combined Arms bonus.
- Light Armor and Self-Propelled Rocket Artillery can together form fastest Combined Arms divisions in the game.
Some types of units don't mix well and combining them together should be avoided.
- Mountaineers lose almost all their terrain bonus in the mountains if Artillery is attached to them.
- Artillery attached to Marines will ruin their amphibious attack bonuses.
- Attaching any other type of brigade to Paratroopers will remove paradrop ability from the whole division.
- Light Armor as exploitation unit shouldn't be mixed with heavier and slower types of divisions.
- Mixing Infantry units with Self-propelled Artillery will be a waste of resources since the only advantage of Sp Artillery over normal Artillery is their speed. Normal Artillery should be used instead.
- Super-Heavy Armor slows down even Infantry and its usage should be limited to stationary defense units.
- Militia and Garrison slow down Infantry so mixing those two should be avoided.
Given that the best hard units are also fast, it makes sense to group them with fast soft units so as to take advantage of the Combined Arms bonus. The choices here are Engineers, Motorized, Mechanized, Armored Car, Self-Propelled Artillery (normal or Rocket), and questionably HQ.
Mechanized is right out because it requires a large number of upgrades, to the point where it is not appreciably cheaper than the more-powerful Armour.
You can have up to 20 brigades without stacking penalty (4 divisions with 5 brigades each). Beyond this, the extra efficiency of using extra support brigades instead of using heavier combat brigades is probably not worth the extra stacking penalty—it would have to be at least 20% more efficient than using heavier combat brigades to be worth it, not to mention the higher supply/fuel consumption.
With a standard 10 width front, the easiest way to achieve 20 brigades on the front is 4 divisions with 3 combat and 2 support brigades each.
As such, depending on your IC / manpower ratio, the optimums would probably be something like
- Mot x 3 / TD x 2
- Arm x 3 / SP Art, AC, or Eng x 2