You couldn't be more wrong.
The overalls, the moustache, and the vitriolic adherence to a working-class background are the trademarks of the Rumblers, the Steam's local mob. The Rumblers were born out of necessity. Following the Great Strike, a great deal of the workers in steam factories began their own sympathy strikes. Now that the Imperial Legions were busily at war, the factory owners were forced to deal with things themselves. So they did. They hired a small army of strikebreakers and sent them to work breaking into peoples' homes, terrorising them and generally pushing folk around.
It worked. The steamworkers' strike was broken, and the strikebreakers were paid and let on their way. Unfortunately, when one gets a large number of big, heavily-armed men in one place for a big job and then disbands them they have a tendency to gravitate towards organised crime. It wasn't long before the Rumblers had evolved into their current form.
Power in the Rumblers isn't hereditary; they recruit people who they think are useful, and push upwards people who turn out to be competent. Their inner politics is not democratic as such: you advance when somebody high-up notices that you're doing a much better job than your superiors, and promotes you.
At the top there are a group of four men, nicknamed (in a move characteristic of the nonexistent sense of humour of the Rumblers) the Foremen. Each of these has his own chain of command, and the structure is not at all regimented: members don't have ranks or numbers or even authority over anybody but their own teams of goons.
In style and appearance, the Rumblers stay true to their working-class ethos: they are generally middle-aged, paunchy, gruff, no-nonsense businesslike men who enjoy a pint of best and a read of the newspaper after work. Take the staff of a 1950s Welsh slate-mine, arm them with crowbars, pickaxes and various other easily-available factory implements, put them in charge of a major crime cartel and there you have them.
The Rumblers are still hired out by factory owners who need dirty work done from time to time. Apart from that, they have a couple of other pastimes. They like to enforce their own form of justice on the streets of the Steam. There is now an unofficial curfew after midnight; anyone out later than that can expect trouble from large gangs of men. They collect protection money. They have a complete monopoly on every pub in the Steam.
More than anything, the Rumblers spend countless energies feuding with the Steam Union. Not for any particular reason; in fact, it's been noted that if they were to settle their differences and co-operate they'd be a true force to be reckoned with. But there's far too much bad blood and far, far too many vendettas between the two groups for that to happen any time soon.
The Rumblers are beset on many sides by enemies:
The Steam Union ("Lazy wimps who just want to get out of doing a decent day's graft.")
The Columna ("Rich snobs, born wi' a silver spoon in their mouth.")
The Kellor ("Bloody immigrants, coming into t' city and taking all our jobs.")
The Grey Order ("Bunch of weirdoes if you ask me.")
Clockworkers ("Pansy-faced prats fiddling about in their workshops all day.")
Anyone richer than they are
The University
...
etcetera.
While the Rumblers thoroughly detest all of these groups, not all of them hate the Rumblers with an equal passion. Most of the Rumblers' loathing takes the form of muttered comments and grumbling conversations about how the world'd be better if they were all gotten rid of: the Rumblers rarely actually *do* anything about their enemies.
The Rumblers do quite get on well with the Dockyard Rats. They have sufficient similarities that it'd be quite hard for them not to. They don't have much of a problem with the Daynann, either; they respect their history of life at the bottom. Indeed, when the Columna or Kellor want to deal with the Rumblers, they frequently do so through their Daynann contacts.
The Rumblers also don't mind Colonel Zero. He's exactly the kind of honest, no-nonsense leader they respect. This doesn't mean that they wouldn't consider him an enemy if he did something that made their lives harder. But they would at least respect him as an enemy.
0: You live in the Steam. You don't associate with the Steamworkers' Union, or if you do then you keep it quiet. You do what the big men on street corners with crowbars say, because you are scared of them. If they find someone beating on you, they will stop them and send the both of you home.
1: You're no longer so scared of the men with crowbars, either because you are one of them or because they nod and smile at you. You're given instructions: places to go, strikes to break, faces to mess up, or things to produce.
2: You are trusted with a little authority. People smile at you and recognise you. You drink in the back rooms of the Wrong Pubs with middle-aged men, and talk about how things used to be better.
3: Middle ranking. You know one of the Four Men who run the Rumblers, and they listen to what you say. Most of the people in the Steam know you by name, even those who've not met you. You get an automatic 'moderate' income, and can try to get 'minor' purchases made for you. If you ask the men with crowbars to do things, they are likely to do as you say.
4: You are one of the Four Men. You get an automatic 'comfortable' income and can try to get 'notable' purachses made for you. The Rumblers hang on your words. [GM only: It's only at this level that the player finds out that his orders are *actually* coming from the Merchants' Arm.]