Ducks was close with christy tick. Tick was close to amuso and casso. Thats really how and why it happened.
Its no bs that ricciardi and tumac thought luongo would be boss. He had power and was from the bronx. A lot of guys thought it would be loungo. Thats why casso killed so many guys. He knew many guys were loyal to the bronx and luongo. He needed to keep sending messages.