I am DMing an homebrew DND 5e adventure. My players are going to defend a village from an orc tribe.
The village will have around 100 armed farmers. Players also gained support of a local dwarven mining expedition (around 30 dwarves), and freed an enslaved kobold tribe from the orcs (about 15 surviving kobolds).
The village will be defended by 100 farmers, 30 dwarves and 15 kobolds against 50ish orcs and 30ish goblins.
They don't know the exact numbers, I will adjust depending on how they will prepare for this.
I took a look at Unearthed Arcana mass combat, but I think it's unlikely to be fun, interesting or balanced for this type of battle.
Some flaws I've identified in Unearthed Arcana for my case:
With units compromising of max 25 units, BR ratings will be extremely low. Most units would be hit once and be dead, or not be hit and nothing happens. For example a unit of 15 orcs (BR 3) against a unit of 20 armed farmers (there is no CR for farmers.. but I would say 1/4, so 20 farmers will have 2 BR) would have a big chance of dying in one hit without causing any damage.
Having 2 or 3 BR will be a huge difference due to the fact that units will either deal 2 BR damage or 5 BR damage. So if a units have 3 BR it has a chance of surviving an attack, while with 2 BR the unit either takes no casualties or is wiped.
Movement and speed is multiplied by 10, range is not. This means that archer units will be forced to melee very quickly.
Most of the post about mass combat either suggest to use Unearthed Arcana Mass Combat rules (which I don't want to use for the reasons above), or design small encounters and objectives around the battlefield.
While the second option could work, I would like to let the players actually command small units around the battlefield. They will spend a couple of sessions preparing traps and strategies to help them in the battlefield (pitfall traps, fires in the fields, ambushes..), and I think they would enjoy to see their result in a "battle" environment.
Is there any system that can let the players play out the battle, more suited to my case?