Running 4 or more video meetings concurrently in channels

I am teaching English on line to a group of 10 students.  While it is "easy" enough to break them into say 3 video sub meeting groups from the main channel - that I can monitor.   I understand that I (as monitor/host/teacher) of main group cannot be "on hold" for more than 3 or 4?  of these groups at same time.

I realized that I can set up several more "groups" - let say I want to separate them into 

5 pairs.  I want to be sure I understand how to do this correctly.    Am I right that I will  need to hang up completely from some of conversations in order to keep that many going at a time?   And, if I do that, will I then be able to find again and rejoin conversations I've hung up on?