Good news to announce!
Coop-Secure-Spawn-Areas is now pretty stable on multiplayer sessions! It's still work-in-progress, but you are now able to create forces, join them and set the diplomancy of those forces. You are also able to clone the spawn starting area, but it's ugly atm.
This mod creates teams and also modifies the map to have separated secure starting spawn areas.
Think of each Base for each Team.
Enjoy and have fun!
https://mods.factorio.com/mod/coop-secure-spawn-areas
FYI: Development on this project is canceled. If you want to edit this, fork it and create PRs! <3