Issue: Junior level employees, who have allegiances to separate leaders, have an acrimonious relationship that leads to conflict. Conflict results in phone call from one leader to another.
Employees come with personalities. Unless their conflicts create true obstacles for the business, or reflect unprofessional conduct, it may be best to allow them to resolve the conflict themselves. Throwing an elbow is O.K. as folks jockey for position and address what they consider the failures of others than impact their ability to succeed. Remember, leaders are not able to discern their history – who pissed on whose head first.
Either do not address the matter or communicate a simple reminder that part of their job description is to maintain a working relationship with their peers and to conduct themselves professionally. Note that further conflicts will be noticed by leadership as a failure to maintain that relationship. Step in when needed, not when asked.