I will write about Nobunaga's army before and around the Battle of Okehazama. It was small at the time. However, it grew big when he had Japan to himself.
It starts off with Nobunaga on top.
Renshi (Brother of a nobleman)
Karo (House Elders)
Busho (Generals of Nobunaga's army)
Hatamoto (Direct vassals to Nobunaga. This is the largest group in Nobunaga's army)
Riryo (Officals to Nobunaga's army)
During this time period, almost of Nobunaga's army came from the home province of Owari. They were familiar with Nobunaga and his tactics. There were no outsiders during this period.
The Hatamoto consisted of Nobunaga's horse guard units, pages, the adult group, and the Red and Black Cowl units.
The Horse Guards (Umamawari) according to Lamers, served two important duties. They were Nobunaga's storm troopers and bodyguards (Lamers, Japonius Tyrannus, p. 31). Lamers also stated that the Horse Guards were created after Nobunaga took full control of Kiyosu Castle in 1555 (Lamers, p. 30). As for the Red/Black Cowls, they were the elite unit in Nobunaga's Horse Guards.
As you can see Nobunaga started out small then the army became larger once he obtained more power. The information stated above is the start (Before and After 1560).
Taniguchi Katsuhiro's Nobunaga no Shineitai is a great book on Nobunaga's bodyguards. A must have.
If anybody knows professional editor, by all means let me know. Thank you.
Tenka no tame!