Because the unix permission model sucks, it is very hard to have a shared directory where everybody has full access to each others files. The same is true when making a shared samba archive. Luckily, samba has forcing options.
[archief] comment = save stuff here path = /path guest ok = yes writeable = yes browseable = yes force user = samba force group = samba create mask = 0660 force create mode = 0660 directory mask = 0770 force directory mode = 0770
The key here is the force modes.
Linux file system’s do allow for easy control with granularity similar to OEs, Windows etc. Use the commands getfacl and setfacl. The default switch is the key to having any new files granted with the desired permissions for any user/group you desire, not just the standard user/group ones.