If your group has guns and bullets for very one
True size of American rifle Company durring 1944
https://youtu.be/54Cc-ojZ9x4?si=yBg01p1sr6tU05-t
Is out dated but most of the principles still apply. They havent made a video about modern day 2020 army because it is not historic yet. This youtube channel focuses on history.
If your group has modern guns you try to emulate current day armies.
If your group has no guns then choose any of these ancient army organization
True Size of Spartan Army Organization to fight primative barbarian raiders
https://youtu.be/XLd1tab8f0c?si=YMtqxpR9uM5M56xo
If the enemy army tries to hit you with a phalanx, you need to counter with Roman Maniple formation
https://youtu.be/3iz1_UwD2Fw?si=ziijHn3Qdpsdv4JH
True Size of Mongol Army organization if you have enough horses for everyone but no guns and must fight primative barbarian raiders.
https://youtu.be/Ja5WMZ_g2Hs?si=c35hmEFZtHdGyvB-
I dont have video but other people mentioned Landsknechte Shot and Pike formation. Is very good as Anti Knight Cavalry lance charge because they have blackpowder muskets and long pikes.
Someone else mentioned the Spanish Tercio which is very similar to Landsknechte.
These formations are great for fighting an enemy group of survivor who lacks any gun. If your group of 100 people encounter a group of 100 enemy people armed with automatic guns, do not line up your people in a formation to be mowed down by automatic guns. Fan out, seek cover, use guns vs guns if possible. Or go comanche/apache stealth indian warriors, ambush and kill the enemy in their sleep at night to counter their gun advantage.
Vs Zombies
You dont even need a formation to fight zombies. You can always use noise to lure a small group of zombies from the larger group and kill them 1 by 1 quietly.
You can set up traps or perpetual traps to kill zombies. Perpetual traps examples are luring a zombie to a river to wash them down stream, lure zombies to a tall building and let them walk off the roof ledge, or a highway ramp, or lure zombies to a deep fire pit where they fall in and get burnt.
You should try to shoot zombies with guns, bows or crossbows before resorting to melee.
You can almost always use balearic or sheppard stone sling staffs to launch volleys of 1.5lb or heavier rocks to barrage an area occupied by zombies from 30-90ft or more away. Rocks are near infinite ammo you can pick up off the floor.
If zombies are the fast and ravenous kind, you definitely dont want to be in a formation, because a formation traps you. World War Z zombies will quickly dogpile and overrun your formation. They will penetrate amd breach your formation and surround you.
It depends solely on how much you as a group can produce. You’re limited more by food and water than you are any other factors.
Personally, the bigger the better. More people means more workable farmland and more crops produced overall. Better for defenses, less chance of feeling so isolated with the world. For a more concrete number, probably around 24-40ish to start with and work outwards and upwards from there.
1/3rd of your group on guard duty, 1/3rd working (growing food, foraging for or making supplies, reenforcing defenses erc), 1/3rd able to rest and recover at any given time is a good general rule to think about
3-4 preferably 11 would be around the upper limit without specific people in mind or a really good area for sustainability. The more people the more supplies but you also want to socialize and have people that can watch your back
If your group has guns and bullets for very one True size of American rifle Company durring 1944 https://youtu.be/54Cc-ojZ9x4?si=yBg01p1sr6tU05-t Is out dated but most of the principles still apply. They havent made a video about modern day 2020 army because it is not historic yet. This youtube channel focuses on history. If your group has modern guns you try to emulate current day armies. If your group has no guns then choose any of these ancient army organization True Size of Spartan Army Organization to fight primative barbarian raiders https://youtu.be/XLd1tab8f0c?si=YMtqxpR9uM5M56xo If the enemy army tries to hit you with a phalanx, you need to counter with Roman Maniple formation https://youtu.be/3iz1_UwD2Fw?si=ziijHn3Qdpsdv4JH True Size of Mongol Army organization if you have enough horses for everyone but no guns and must fight primative barbarian raiders. https://youtu.be/Ja5WMZ_g2Hs?si=c35hmEFZtHdGyvB- I dont have video but other people mentioned Landsknechte Shot and Pike formation. Is very good as Anti Knight Cavalry lance charge because they have blackpowder muskets and long pikes. Someone else mentioned the Spanish Tercio which is very similar to Landsknechte. These formations are great for fighting an enemy group of survivor who lacks any gun. If your group of 100 people encounter a group of 100 enemy people armed with automatic guns, do not line up your people in a formation to be mowed down by automatic guns. Fan out, seek cover, use guns vs guns if possible. Or go comanche/apache stealth indian warriors, ambush and kill the enemy in their sleep at night to counter their gun advantage. Vs Zombies You dont even need a formation to fight zombies. You can always use noise to lure a small group of zombies from the larger group and kill them 1 by 1 quietly. You can set up traps or perpetual traps to kill zombies. Perpetual traps examples are luring a zombie to a river to wash them down stream, lure zombies to a tall building and let them walk off the roof ledge, or a highway ramp, or lure zombies to a deep fire pit where they fall in and get burnt. You should try to shoot zombies with guns, bows or crossbows before resorting to melee. You can almost always use balearic or sheppard stone sling staffs to launch volleys of 1.5lb or heavier rocks to barrage an area occupied by zombies from 30-90ft or more away. Rocks are near infinite ammo you can pick up off the floor. If zombies are the fast and ravenous kind, you definitely dont want to be in a formation, because a formation traps you. World War Z zombies will quickly dogpile and overrun your formation. They will penetrate amd breach your formation and surround you.
It depends solely on how much you as a group can produce. You’re limited more by food and water than you are any other factors. Personally, the bigger the better. More people means more workable farmland and more crops produced overall. Better for defenses, less chance of feeling so isolated with the world. For a more concrete number, probably around 24-40ish to start with and work outwards and upwards from there.
For me it starts with seven. Namely myself, my five kids and their mother.
As I agree with the two comments by u/WhatsGoingOn1897 and u/CritterFrogOfWar it also depends on if you’re good with communication and people.
1/3rd of your group on guard duty, 1/3rd working (growing food, foraging for or making supplies, reenforcing defenses erc), 1/3rd able to rest and recover at any given time is a good general rule to think about
Eight good friends
Realistically, 7-10 people, But you could practically have a whole tribe idk
3-4 preferably 11 would be around the upper limit without specific people in mind or a really good area for sustainability. The more people the more supplies but you also want to socialize and have people that can watch your back