The 'maki' (pasture for horses and cattle, written as '牧') was originally defined as a horse farm (written as 牧場) in Kanto region and provided the condition where a handful of bushi with special units could formalize if only a few of those horses could stand training.
馬の中のごく一部がそれに堪えられたとすれば、武士という一握りの特種技能集団が成立し得る条件を備えているのは、関東においてはそもそもが馬の牧場を意味する「牧」であった。