What's wrong with my disk and apfs volumes?

I'm learning/trying diskutil, newfs_apfs and other disk command on macOS.
My idea is actually this: a) Create a 1 GiB container b) Add 5 volumes of 200 MiB size in the 1 GiB container I run these commands. Delete container diskutil apfs deleteContainer disk5 Container1 OK Create container diskutil apfs createContainer disk0s1 OK Now, I start to create the volumes, 200 MiB each (1 GiB can contain 5 volumes of 200 MiB) newfs_apfs -v "Volume1" -s 200M -A disk5 OK newfs_apfs -v "Volume2" -s 200M -A disk5 OK newfs_apfs -v "Volume3" -s 200M -A disk5 newfs_apfs: unable to format volume inside /dev/disk5: Result too large Why?
The command diskutil list reports this situation: /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.1 GB disk0 1: Apple_APFS Container disk5 1.1 GB disk0s1 /dev/disk5 (synthesized): #: TYPE NAME SIZE IDENTIFIER 0: APFS Container Scheme - +1.1 GB disk5 Physical Store disk0s1 1: APFS Volume Volume1 209.7 MB disk5s1 2: APFS Volume Volume2 209.7 MB disk5s2 As you can see the container's volume uses only 420 MB of space and I have at least space for two other volumes.
What's wrong?