I think Jimmy was also the one they thought had the biggest chance of getting out on appeal, but no dice.

If you remember after the trial everyone else thought that Calabrese Sr.'s awful testimony sunk everyone else, that is why they all wanted separate trials.

Regarding Secrets, yes they were all old, but it really wasn't the feds going on a witch hunt. Calabrese Jr. approached THEM about flipping. Then they ran DNA on the Fecerrota glove and had Nick by the neck, and he flipped.

So they went after everyone they could. That's what they do.