Another example would be Lucky Luciano and Dutch Schultz.
They were both gangsters who shared the same basic ideology.
So why did they fight?
Answer: because - they were both gangsters who shared the same basic ideology.
They fought over turf. They fought over territory, wealth - whatever there was to take. So did Hitler and Stalin.
I had a great Uncle who was concilari to Lucky, but Lucky did not want to listen.