It is easy to tell the three from the rest of their crew, because of their blue jackets. All three come with the crew collection.
Charlie-- Leader of secret Triumvirate Treason gang, searching for the finer things in life.
Bartholamew Jackson-- Devious Triumvirate Treason strategist with a taste for fish guts.
Stevedore Springfield-- Easily angerd weapons master for the Triumvirate Treason gang.
All of that came from the official Crew Collection set.
Lockpick Cabot from Smugglers Fort 2.0 is a Privateer also with a blue jacket but he is NOT part of the Triumvirate Treason.