The Butcher Boys are not quite a gang, they are more a group of rough and tumble men with a common occupation, cooking, and a common interest, hurting other people. The Butcher Boys work in the kitchens, slinging food for other people, likely making close to minimum wage. They are henchmen for the boss, usually low profile but close at hand.
and always ready for a good fight.
The Waiter is just a guy, in a restaurant, who takes food from the kitchen to the tables, and empty plates back to the dishwasher. Frequently smokes, talks a lot of smack, and is the most likely to touch the customer's food out of spite. He's a street tough kid, and what he lacks in a specific fighting skill or style, he makes up in enthusiasm and foul language.
The Line Cooks
The line cooks are a group of guys who plate the sides, serve appetizers, wipe plates, and generally do the menial labor of the kitchen. They are foreign, speak a common foreign language, and a general dislike for anyone who isn't their ethnicity, but minorities tend to be closer to okay in their book. They know how to fight, they like to fight, and what they lack in coordination or training, they make up for in numbers. They tend to be armed with kitchen knives, and make for dangerous opponents.
The Big Guy
Nominally a line cook, the Big Guy towers over the others, and when fighting starts, he drops his plates and goes for grapples and body throws. If the fight gets really ugly, the Big Guy is the one who tries to throw people on the grill, in the fryer, or dumps heavy containers of food prep materials on others.
The buzzard is a skinny guy, and older, the sort that is really skinny, but can out-eat three people. The buzzard has a real knife, and knows how to cut a person up badly. He has real street experience, and has hurt people in the past. He doesn't enjoy doing it, which means when he does hurt someone, there is a deterrent factor coming into play.
The leader of the kitchen staff, or just the most senior line cook, the chef is generally in charge, and will be the second person in the kitchen fight. He has a big knife, he's got a mean swing, and he doesn't like fights breaking out on his line, or in his kitchen. He swears like a dozen sailors, and can give tactical commands to the stuff to keep them at an advantage.
The waitress is often close to the waiter, but as often as not has an alcoholic beverage of some sort. She is armed with ice picks, wine bottles, flying glassware, corkscrews, and generally comes in as a wildcard.
Like the waitress, the hostess is usually out of a fight, but if things turn ugly for the Butcher Boys, she has an ace up her sleeve. Of the Butcher Boys, the Hostess is the only one who carries an actual pistol. Used to dealing with the randy kitchen staff, drunken customers, and general assholish behavior, she doesn't panic and run (like the waitress) but knows the difference between a body shot, and shooting center mass.
Additional Ideas (1)
If I were to suggest, it needs more hot sauce and poison!