Kamon is family emblem

Upper emblems are described as most popular family emblems, best tens.
Every family has its own emblem.
In battle era of Japan, Samurai family, Clans had some emblems and they used it in some case.
For example, at the battle field, at the ceremony, in daily use, etc.

Sekigahara war held at about 1600 in Mino province.
I can see many flags installed on their squadrons.
Every worriers might keep watch their friendly force's emblem.
Every commander might see and decide their position according to enemy and friendly emblems where they were.
Kamon, family emblem must have made them taken pride.