Regimental organisation and/or "ranks" during Sengoku Jidai?

[Gauloisier de la Gauloiserie]

Hi there
I guess that during the Meiji era those were implemented in Japan on the US/EU model.
But before?
Did the "samurai armies" had a rank system, with NCOs, Officers and so on?
(have read about ashigaru taishou, but is it more a function than a rank?)

And concerning the units, did they have name, numbers, somehting like 45th archer unit or 21st yair samurai unit?

Thanks for your replies

[Juggernaut]

Did the "samurai armies" had a rank system, with NCOs, Officers and so on?
(have read about ashigaru taishou, but is it more a function than a rank?)

Any army would need a hierarchy and chain of command in order to function, and Samurai weren't exception. But you have to understand that Samurai were a social class, and not a modern professional military.
"Ranks" within the army were directly reflected by the often hereditary social position, size of fiefs and titles one held within the clan, not by one's ability.

An example of army organization can be found in Iwatsuki-shū in 1575, Houjou clan's "brigade" that was based in castle Iwatsuki of Musashi province. The "officers" were organized in a way like this:

General:Ōta Gengorou, son of Houjou Ujimasa(Also the castle's commander)
Captain of the Twenty runners:Baba Genjūrou
Captains of the camp:Kasuga Zaemon, Hosotani Gyoubu-zaemon, Miyagi Shiroubē, Fukushima Shirouemon
Fire captains(The night patrol):Kasuga Saemon, Hosotani Gyoubu-zaemon, Tachikawa Touzaemon. Miyagi Shiroubē, Fukushima Shirouemon, Tachikawa Shikibu.
Captain of the 1st baggage train:Kasuga Saemon, Fukushima Shirouemon, Tachikawa Shikibu.
Captain of the 2nd baggage train: Miyagi Shiroubē, Hosotani Gyoubu-zaemon, Naka Chikugo-no-kami.

The troops were arranged in the order below, followed by it's captains.
120 banners: Naka Chikugo-no-kami, Tachikawa Touzaemon, Shioda Takumi-no-suke
600 Pikes(4.5m): Fukushima Shirouemon, Toyota Suou-no-kami, Tachikawa Shikibu, Kasuga Yobē
50 Guns: Kawaguchi Shirouzaemon, Mano Heita
40 Bows: Ozaki Hida-no-kami, Kourai Ōino-suke
250 Samurais on foot: Yamada Yarokurou, Kawame Daigaku, Shimamura Wakasa-no-kami
500 Samurais on horse:Shibue Shikibu-no-Daiyū, Ōta Uemon-no-suke, Kasuga Zaemon, Miyagi Shiroubē, Oda Kamon-no-suke, Hosotani Gyoubu-zaemon
20 Runners: Baba Genjūrou
Total 1580

And concerning the units, did they have name, numbers, somehting like 45th archer unit or 21st yair samurai unit?

AFAIK, units were simply referred by the name of it's commander or the region they came from.

[Gauloisier de la Gauloiserie]

Cheers!

[Juggernaut]

Another important aspect to consider is the Yoriko-Yorioya system. This is something I still don't entirely understand, but you can read the gist of it here.

[GE Longstreet]

For what I know about the Ashigaru (low status footsoldiers below the samurai caste) had a system of officers and NCOs.

Ashigaru Taisho - a combination of rank and position (Taisho = General [also regimental commanders were Taisho] , so "General in Command of Ashigaru")

When available ashigaru were made into regiments, and 2-3 of those in a brigade; where each brigade was under command of an Ashigaru Taisho.

Ashigaru Kashira - a captain in command of a company (ca. 150 men)

Ashigaru Ko Gashira - a lieutenant in command of ca. 30 men

Ashigaru Teppo Ko Gashira - a lieutenant in command of ca. 30 strong "firearms squadka" (archers, later a combination of arquebusiers and archers)

[Ying, Duke of Qin]

To suggest that Sengoku era military structure was organized in the same way Europe was during the Napoleonic era is a gross overgeneralization. The answer differs widely even amongst historians in the same clan, and the sources are very disorganized. I do not think anyone is capable of giving you an answer, short of the daimyos themselves.

Let us take the Takeda for example.

In the Koyo Gunkan, we have that the basic unit of the Takeda was organized in groups of 25. One commander, two mounted soldiers, five non-combatants (flagbearers, weaponbearers), eight spearman, eight archers, and four gunners. Five or six of these groups would be led by a commander, who would then act as officers. These larger groups are known as ban, which can be thought of, loosely, as "regiments."

However, in a later work, the Shingen zenshu massho, by Obata-kan-Hanbei, he mentions that each ban possessed 50 mounted soldiers, 390 infantry, and 238 non-combatants. In a slightly later work, composed by Hojo Ujinaga, yet another prominent military historian of the era, he gives a blanketing figure of 744 soldiers, with no attention paid to the unit composition.

Clearly, they can't all be right. Given that all of these works are composed around relatively the same time (late 1500s to early 1600s, the Hojo one is a bit later), you can begin to see the difficulty in figuring out what was going on. They may not be able to be all right, but they were unlikely to be all wrong either.

And this is just one clan - a major one at that.