How would an Army assign troops to units?

Question

The United Commonwealth Army is a full volunteer force, made up of full time professionals, with a large amount of trained reserves that it can call upon in time of crisis.

However, I have been having trouble with connecting the trained soldier to the actual formations that are deployed. On Earth, I know that the regimental system, where soldiers are assigned to battalions in regiments, which are then amalgamated into brigades. However, the world I made has its regiments as a frontline unit, replacing brigades.

One important thing is that soldiers recruited in one place that are not reserved will often be sent to deployments far away from their home countries, often deployed in foreign allied countries for a long time.

My current theoretical system involves splitting recruits into companies, which are then assigned to various pre-existing battalions already deployed, which assist in training and providing the experience needed. In this arrangement, each maneuver regiment will have 3-4 combat battalions, each with 3-4 companies of either armour or infantry troops, of which one will be made up of the relatively fresh recruits.

However, I imagine there might be some problems with this. Hence, I was hoping to get some recommendations as to how a large professional Army would go about recruitment.

Edits)

Extra Info:

1. The World is a mixture of highly modern technology, slightly better than on earth

2. The countries are very much democracies, ranging from constitutional monarchy to republics, with a wide variety of human cultures.

3. Funding is very high, with a minimum 3% of the total GDP of all of the dozens of member nations being chipped in

4. Nations have surrendered their military control to the central UC Army/Navy, while still retaining combined control over the armed forces' use via the Armed Forces Council, similar to the Atlantic Council in NATO, and the Council of Nations, made up with the heads of state of the countries.

5. Poverty is generally lower than on Earth, as all of the UC nations are developed or developing quickly.

6. Military traditions run deep in many countries, especially in the Weslich Empire, where the bulk of the troops come from.

Answer 1

Step 1. Forecasting, which is basic math.

My force structure for next year calls for a total of 5285 wheeled vehicle mechanics. I currently have 5223. Of those, enlistments expire for 915. I know from experience that about 20% of my expiring enlistment will re-enlist, that 4% of my force will require emergency releases, or become disabled, or convicted of a crime over the next year. I also know from experience that about 5% of my mechanics will become promoted to sergeant. Finally, I know from experience that around 8% of mechanic recruits wash out (fail) during training.

If there is fighting going on, then you also estimate the number of casualty replacements you will need to recruit and train.

Using the USA for an example, Basic Training for most new enlistees occurs during the summer, though courses run year-round. Advanced training for each soldier's specialty follows in the autumn, though again many courses occur year-round. Let's assume my mechanic school runs classes of 150 seats each.

Therefore, I'm going to tell the general in charge of recruiting that I want them to enlist 1350 new soldiers (= 9.0 classes) over the next annual cycle, and send them off to training as wheeled vehicle mechanics. I will have 15 vacancies left over (about 0.003% of the total mechanic force), which suggests offering some re-enlistment bonuses to increase retention from 20% to 22%.

Step 2. Tracking vacancies, which is even easier.

Your S1 (Personnel) office handles this routinely. Units aren't a "bunch of guys". They are structured. They have positions, which are either filled or unfilled. Any S1 can produce a list of vacancies for all of their subordinate units. Tracking and filling vacancies is a big part of what they do.

Step 3. Prioritize units, which is very easy

Units going into deployment or active-mission rotations have the highest priority. Units recovering/reconstituting after deployment or active-mission rotations have lower priority. Reserve units often have the lowest priority.

Step 4. Assign class graduates to priority units. Easiest job of all

So here's what it finally boils down 9 times each year (9 classes):

• I have a list of around 120 newly trained mechanics who will graduate from school next month. (That's one class of 150 minus approx. 8% washouts). Let's say that I have 122 this month.
• I have a vacancy list of around 150-or-so current vacancies from around the military, ranked in order by unit priority. This list includes high-priority vacancies that will occur soon.

The top-priority 122 vacancies each get one class graduate. It's pretty much that simple. Lower-priority vacancies (#123 on the list and below) wait for the next class. Or maybe the class after that.

Answer 2

You want a futuristic feudal levy

"Fresh recruits forming companies which join army as a unit" is exactly how it worked back in medieval time. A lord was raising a force for a war. He might have had a few seasoned knights, but the bulk of recruited force were peasants without much training. After assembling, this troop would march to join the king's army, and it would stay as a separate unit, with surviving peasants becoming better, sometimes even professional soldiers.

Unfortunately, levies could not stand well against regular troops, much less against well-trained knights. As soon as European economy was able to afford it, levies gave way to professional armies, with new recruits training alongside veterans.

Why this scheme might work in the future? We need a mechanism to erase the gap between sergeants and rookies and make years of military training irrelevant. There are a few options here:

1. Futuristic war is just like a videogame. What teenager does not like to play videogames? And how many adults can beat a teenager at it? Sure, we might still need a few responsible adults to lead that bunch, but other than that, a rookie company is as strong as any other.

2. "Tank, I need a pilot program for a B-212 helicopter" (c) What if any kind of training can be uploaded directly into the brain in mere seconds? We can have an army of veterans any time we like it. Just give us fresh recruits.