Yes, you can add the Team Lead to another Team as a team member.

Firstly you should remove the Team Lead as a Team Leader. Then add him as a member of another team in Salesforce.

Here is what you need to do 

  • Log in to Salesforce as a System Administrator
  • Go to the Teams tab and remove the team lead name from Teams

  • Go to the Users tab, and assign the same user to another team from the Assign to Team field. Save it.

Now the Team Lead is added as a Team Member to a Team.