yeah, no, imposing rigid social hierarchies on your setting "because Asia" would be an example of Orientalism. to be fair the shogunate did make a whole to-do about social classes in an effort to legitimize their rule, but you're right in calling out how imposing this on all Asian settings is weird.
yeah I'm also constantly disappointed in official samurai options. personally I think we should have two different samurai sub-classes, one for the Sengoku era armor clad samurai who mostly fought on horses (also not exactly exclusive to Japan, so labeling it as "samurai" is weird), and another for the Edo period samurai who wanders and uses his sword to help useless villagers. yeah that last one is tropey and not realistic, but it is fun and worth exploring imo.
also while we're on tropes: ninja. I brought this up in a different thread, but I'm disappointed how they're almost entirely based on the Western interpretation of ninja that was created like 30-40 years ago and hasn't aged at all. I'd totally play a character who's sneaky and uses cool magical abilities to fight enemies. it's not like the west is ignorant of these ninja tropes either, they make their way here via Japanese pop culture, but we don't even use the tropes made up by the country where ninja come from lmao.
I feel like that has already been done with the standard Fighter class.
If you go with a Strength-based Fighter, then you are going to want heavy armor and a polearm/heavy weapon.
If you go with a Dexterity-based Fighter then you are going to want minimal armor and use only a rapier or a rapier and short sword. Just retheme the rapier into a katana.
You can make both Tadakatsu Honda and Miyamoto Musashi using the Fighter class without having to have a separate "samurai" class.
good for... them, we just had a discussion of how applying an honor system to any Asian setting is an example of Orientalism. if you were trying to emulate a specific culture that had a system like that, then okay, but not every Asian culture has this.
Samurai having an "honor system" at all is very much an invention of Meiji Era Japan when it was psyching soldiers up for World War II. In truth, they were far quicker to switch sides in a war-- either during or immediately after the battle-- than happened with anyone but mercenaries in Europe. There was so much "I defeated you in battle, now you work for me" that it may as well have been considered the norm. And some of the biggest names lost battle after battle before finally getting cornered and either dying or becoming a retainer of their enemy-- meaning that running away when the battle turned against them was very much in their character.
Sure, there are instances in those who stood against impossible odds bravely to protect their master or who committed suicide after carrying out an order they disagreed with or when their side lost-- but those more famous for doing so were mostly not even technically samurai. And the last one was mostly done because they were so afraid of what would happen to them if they were caught.
And then one could get into the instances where samurai killed the children of their former enemies lest they grow up into enemies that slaughter their entire families (because the whole "samurai" thing started with a pair of brothers who did exactly that-- got spared/adopted by their father's enemy then, once adults, used their position to slaughter their father's enemies whole family and took over the country) or when they forced their own relatives to commit suicide in order to avoid a potential dispute over succession.
In fact, the main guy who started the samurai tradition, Minamoto Yoshitsune, won a ton of his battles through entirely dishonorable tactics. For example-- in a battle on boats, instead of fighting the enemy soldiers, he had his men shoot the peasants who were rowing the boats.
So it makes absolutely no sense to impose an honor system on them any more so than it does for knights-- because they were no different.
The whole idea of a "bushido code" was made up by Miyamoto Musashi-- a guy, by the way, who was in a couple key battles, isn't recorded as having done anything of note in them, and was on the losing side yet survived-- meaning he ran his ass away every time he was in a real fight. He also claims to have won countless duels-- but any recordings of him doing so always involve him using the dirtiest, most underhanded, most dishonorable tricks possible. And this is the guy who people are going to pick up the idea that samurai are honorable from?
It was adopted in Meiji era Japan in order to serve as propaganda for the war effort-- it is how they got pilots to be kamikaze pilots-- but, by now? Pretty much everyone in Japan is so over believing any of that. The truth is pretty well recorded and depicted in countless games that depict that era. (It is one of the most popular subjects to make games out of.)
Granted-- one is making a fantastical version-- but its not like Europe "Knights" in D&D are expected to strictly adhere to the Code of Chivalry lest one be struck with mechanical penalties. The precise Code of Chivalry isn't even spelled out explicitly anywhere in the books.
So it would be fine if "bushido" were part of the setting as some sort of ideal that no one really reaches and most of the successful people don't even aspire to-- but once in a while you might get a young, green fighter who has "drunk the kool-aid" and totally buys into it. And that can be a fun particular character concept.
But striking characters mechanically for not adhering to a dumb code that even the guy who wrote it never actually emulated? That's just hamstringing players for no reason.