Even without stack ranking, if you lead a team large enough, you get people who are struggling more than others. Sometimes it’s clearly situational: they are more junior and are still learning the ropes, the project is going through a rough patch and it’s hard to deliver, they are going through a rough patch and it’s hard to deliver and sometimes it’s just that their skillset is mismatched with what they have to do. In this case, you have to decide if it’s a case where training will solve the issue or if having someone else there would be better for everyone. And yes, not constantly being in conflict with everyone is also a professional skill.