Every archetype within each faction has a certain idea or style it's going for when designed. Dwarves specialize in armor and tribal boosts. Thrive MO is built around setting up small engines and slamming down large cards that boost them. Some achieve their purposes, others mimic others or fail to achieve what they were designed to do. I'll say ahead of time I'm not extremely familiar with the lore. I just want to get these thoughts out. I know the end result is that nothing will happen, but I think it's still worth discussing. I'll start with the successes.
Melusine Cultists- Amazing design with Melusine. The deck feels like it's worshipping a goddess with her followers(bronzes) carrying out rituals to grow her power.
Siege- Everything dies. Burn it all to the ground. Feels realistic to what it's intended to be.
Warriors- Kill everything. Burn it all to the ground. See above.
Relicts- Are well designed. The base power/carryover strategy is achieved everywhere except for gernichora. She fits into relicts as well as any other MO deck that puts out points(besides the synergy with Selfeater). I'd like to see her reworked to maybe have an effect while in graveyard or something similar. "While in graveyard: whenever you play a relict, increase it's base power by 2 and decrease this unit's base power by 1." Something like that.
Bounty- Feels exactly as intended. Set a target, kill it, repeat. Murder anyone and anything that we choose.
Frost- Weak, but is still really unique. Place your opponent in a world of ice and bash them in until they die of frostbite. Needs buffs, but not reworks.
Mages- Are terrible but again, novel. Extremely slow, and should be sped up, but once they are, the feeling of throwing fireballs over and over will feel really great.
Dwarves- Do not qualify for childcare tax relief. Very fun deck, and one of a kind.
Control ST- Makes sense. The terrorists kill everything with- you guessed it- bombs. They leave nobody alive, except their own.
Vampires- Vampires are not only weak, but don't actually represent what vampires do. Draining feels much more realistic to the purpose. For the assassins of the monster kingdom, vampires sure suck at removing anything.
Elves- Don't need fixing, but are truly all over the place. Some boosting, some damage, but in general not a clear design in mind. Maybe they're supposed to be the basic archetype: a sort of starting place to make variations on in design. Otherwise, they're boring.
Tactics- Shouldn't be all about killing everything. There are defensive tactics too. A special card focused archetype is always interesting, but this one is just a bunch of trading cards. Engine played by opponent, removed by 5p tactic, repeat. Real tactics are carried out by soldiers, so I'd like to see those tactics rely on having allied soldiers to carry them out.
Masquerade Ball- Is not an archetype. Every other scenario is centered around one, but ball is just straight points.
Crimes- Hear me out. Intimidate needs a change. Someone doesn't suddenly become stronger when an unrelated crime is committed somewhere in the city. Gaining coins from it actually makes sense. Like the mafia: makin' money outta madness. Intimidate could be like: Whenever you play a crime, gain one coin or the specified amount. If your bank is full, boost self by that amount instead. Would need rebalancing but would be really cool.
Pirates- Are a mess. Are they self wound? Are they resurrection? Are they control? Or just a sloppy second-handed attempt at all three?
Cache- Prostitutes getting stronger from someone else having money does NOT make sense. Prostitutes are the ones who make the money. There are quite a few places to go with this.
Witchers- Should be more removal based considering they're monster slayers. They're not the type to passively sit around without killing anything.
Symbiosis- Needs more finishers. Boost all allied treants by 3 or something. Dryads living in harmony with nature is nice and all, but the deck is not in any way what someone would imagine. Growing a random dryad to giant size and spawning walking trees just doesn't feel right.
Viy- Sounds good in theory, is mindnumbingly boring in practice. It's an instect that grows by killing people, right? Why not like, Order: Consume a  power unit and increase the number by 1. Cooldown: 1. It makes no sense that the unkillable bug gets stronger by getting killed over and over.
Traps- Are unhealthy, uninteractive, control. There should be mindgames! What card did he put down? What card is safe? How do I play around the different possibilities? Not this uninteractive bs. Nobody likes playing against traps. It's a terrible experience.
Those are the main ones. Feel free to mention any more I left out. I feel very impulsive for publishing so many vulnerable thoughts, because that has never went well on this platform before. We'll see. Let me know what y'all think.