Great post, fathermarcello. Welcome.
I agree 100% about the brothers Pentangelli. Frankie idolized his brother.
I assume that once they got Frankie talking, they could use his information to bring Cicchi around.
I've always thought that Roth set up the entire Pentangelli scenario. I can't see any way that Frankie could be taken into police custody, without leaving a trace that he was alive, unless someone knew he was coming.