Have you read about the Leader Member Exchange Theory (LMX).

According to Hughes et al., 2022, TheLeader Member Exchange Theory (LMX) theory focuses on the leader's responsibility to develop more in-groups and reduce the number of out-group members.

What is your understanding - should the leader work closely with the out-group members to better develop them for the in-group or make it more difficult and eventually terminate them resulting in more in-groups than out-group members.