How to limit Team leader or member in PSO Resource Planner

Hi Team, 

We have created two positions as below for PSO resources. 

1. Crew Leader
2. Crew Member

We need to have only one crew leader in a PSO Team. For this we tried configuring in PSO Requirement screen as below. Our expectation was that after setting the below requirement PSO will show an error if we try adding another Crew Leader within the team in PSO Resource Planner.

But unfortunately it doesn't shows any error while trying to add more than one crew leader. We are able to specify membership and generate shifts for these multiple crew leaders. Everything looks green in the PSO Resource Planner screen for these crew leaders. It means this is acceptable in PSO.