- Barbarian (Path of the Berserker, Path of the Wild Heart)
- Fighter (Banneret, Battle Master, Champion)
- Monk (Warrior of the Open Hand)
- Ranger (Beastmaster) – you can choose to have your ‘beast’ be a robot.
- Rogue (Assassin, Thief)
And I just saw the new Artificer, which would probably also work.
We have a Banneret Fighter noble from the Federated Suns with aerospace distinction, who has main character syndrome (a tongue-in-cheek version of narcissistic personality disorder where he copes with the world
not revolving around him by thinking about life like it's a video game, and everyone is an NPC, and he just needs to do the right quest in order to get what he wants).
Also a pair from the Lyran Commonwealth: an Assassin Rogue from a business dynasty with a distinction in logistics, and a Beastmaster Ranger priest of the Catholic church with a distinction in tactics. Both were refugees from the recent pincer attack by Clans Wolf and Jade Falcon on Steiner space.
An ex-Snow Raven elemental Berserker Barbarian who got drummed out of the warrior caste, became a laborer, then a pirate, then joined the Federated Suns armed forces so she could fight again. Her distinction is infantry.
And finally a naive doctor who's an Open Hand Monk from the Magistracy of Canopus, with a distinction in medicine. He's interested in neurohelmet technology and exploring brain-machine interfaces, and joined the AFFS because the Magistracy Armed Forces wouldn't let him leave the medical field.
So far the only face-to-face combat was when the PCs and their fellow cadets were politicking to see who could get assigned which mech from the unit's roster, and there was one guy who was too much of a jingoistic idiot being hostile to some of the unit who weren't as gung-ho about the First Prince Caleb Davion, so they goaded him into a fight so he'd get disciplined and assigned to Locust duty.
Dude swung one punch at the party's barbarian, and because she was raging, the dude's fist did 1 damage, halved and rounded down to 0.
Next session (probably on January 10) is going to involve both mech combat and then boarding a grounded dropship, fighting past its crew, and trying to recover its flight data.