what is the best way - to rotate accounts between users automatically? (business case described).

Dear Zoom crew and all community, 

I wonder can I solve my business case with Zoom (any licensed account/accounts). 
I have 100+ contractors (fitness trainers) who have weekly 1-1 meetings with our clients (meetings 30-90 min, need to be recorded sometimes).  Max capacity is about 10 sessions at the same time. 

So I am trying to figure out:
can we use just 10 paid licenses instead of 100? The main problem is how correctly assign a contractor with the right license that has not been picked by another contractor at this moment yet (we can do it manually but it's a nightmare).
I assume that zoom somehow can automatically do these assignments. However, not sure though. Could you give me any hints/ideas on what zoom features can do so? 

Thx a lot for any help /tips.