The full rulebook has rules for using smaller scales/tables called Kitchen Table Games (page 32). If you haven't already, you can buy it here or by joining the patreon you can download all the games' full rulebooks as well as the point's calculator to make your own units/gangs/armies.
P.S. I absolutely love your table! Very cool terrain.
Did you enjoy Warhammer Fantasy? Just want some more advanced rules for your games of AoF:Regiments? Check out my fan-expansion, The Lost World!