Fire Tank Pirates

The Firetank Pirates are an infamous and notable rookie pirate crew discovered on the Sabaody Archipelago around the time the Straw Hat Pirates arrived there.

Crewmates
They appear to be based on a mafia family, and many of them are dressed in tuxedos, with coats strapped to their shoulders, and/or wearing cowboy hats. Hence, they (or at least the captain) like Crocodile have a very Italian Mafia aura.

Crew Strength
All of them appears to be consistently armed with rifles, same for their captain, who has an army of men inside of him, that works his body like a castle, thus giving him a military advantages. It is shown that many ride horses into battle. .

You guys have already lost... in sheer military force.

-Capone Bege.

It can be presumed that they are very strong for them to have made it all the way to the Sabaody Archipelago. And for their captain to have such a high bounty.