THE WEAPONS GROUPS CONTROVERSY
The question of when exactly Sengoku troops began to be organised by weapons groups is the subject of some debate among Japanese historians. For most of the samurai period, armies would be composed of feudal bands of warriors leading their own retainers, the band as a whole being a mix of mounted and foot, missile, and melee troops.
These bands would vary greatly in size as well, making it a bit of a nightmare for wargames rules. At some point in the mid to late 16th Century, the retainers of individual vassals began to be separated off into distinct weapons groups.
Historians agree that the causative factor for the shift was an increase in daimyō authority. As the daimyō of the Sengoku period built stronger governmental structures, accompanied by land surveys (to get more of an idea what each vassal could provide), they could fit the vassal into a system that provided structure and security but at a loss of their freedom of action.
The disagreement comes from deciding when the level of daimyō authority was sufficient to compel vassals to give up direct control of their troops.
The question of when exactly Sengoku troops began to be organised by weapons groups is the subject of some debate among Japanese historians. For most of the samurai period, armies would be composed of feudal bands of warriors leading their own retainers, the band as a whole being a mix of mounted and foot, missile, and melee troops.