It feels weird that you have "Tokyo (Japan)" as your location and not just "Tokyo". I don't think there's any other "Tokyo" that has within an order of magnitude the mindshare that the capital of Japan does. I guess some people wouldn't have heard of Tokyo before, but eh, I'd like to give them the benefit of the doubt. Google is also there for the curious.
I read the official translation of 979. I think King is implying they're ALL former pirate captains. I'm thinking the Headliners (who aren't Gifters) are outier forces that parallel Kaido's core crew. That's how the Numbers come after Jack but Who's-Who can be next in line to take a Lead Performer's place.