Hello Jacquie,
You might find this other thread relevant for your case: Request better permission control for organization admin - Product Feedback - Figma Support Forum
One of the many good proposals in that post is exactly the possibility to restrict who can create a team.
For us, I can imagine leaving the possibility to create teams for most people. However we could only accept that with the condition that an Organization Admin can delete a team, which is inexplicably not the case now 