It was a combination. Obviously luck was involved but plenty of mobsters are alive today due to luck.
I mean he sniffed out the Chin's plot to lure him to a sit down in NYC and have him killed.
People always discredit Merlino but I always thought he was a little sharper than everyone gave him credit for. Probably works in his advantage when everyone thinks he is an idiot
But Merlino overcame a lot to rise up in Philly at a young age..he was smart enough to build a loyal following
If I remember right, it was Fiumara who invited Merlino to come up to Jersey for a meeting. Merlino's response was basically, "You come down here to Philadelphia." Probably didn't want to risk being getting the Caponigro treatment.