Capone and his gang of 20 made guys were actually sent by the genovese bosses to establish control for new York. They were at first, a subordinate crew that answered to Joe masseria. But by the end of joe the boss and Salvatore maranzano reign, Capone was considered a separate operation.

The outfit never exceeded more then 80 members in the 50s and 60s. Compared to even the smallest family in New York, the lucchese, who always had around 100+ members. Regardless, bc the outfit dominated all Italian crime in Chicago, which was an extreamly large and populous area, they had too be much more violent too keep their hegemony. And their was a perception by New York families that they were more violent.

Regardless the real power of Chicago came more from geography than pure mucel terms. They had enormous influence on Mafia clans not In the east coast. And while the commission, packed by New York 5 families had the ultimate decision regarding the actions of any Mafia family in the us, Chicago was the ultimate decoder of anything west of them.