We use Security Policies for this. In the policy, you can set the access level for each technician. It is a very manual process, however.
As an example, we have our track-it setup where each technician is part of a group. Example: Server Team. Everyone on the Server team looks at tickets in a dummy technician called "_Server Team". To avoid others in the agency assigning tickets directly to technicians, we change all of the individual technicians as "No Access" in all other Security Policies so only the team bin can be assigned to from users outside of the team.
I hope that makes sense.