The Calabrians are so low key and secretive, they will never be a huge target for the feds.
They can't supplant the New York families while maintaining a low-key profile. This is why it won't happen. They don't want to be on the radar of the feds so they cannot be too ambitious if they want to continue to operate in the area without much scrutiny.
Don't fool yourself thinking the feds or NYPD don't have their eye on them. They don't appear to be a priority for them at the moment but they will when their presence becomes abundant.
