Your question is culturally-aware enough to ask the question. You don't say what role this amalgam culture plays in your story (how it is represented in-world), so none of this is directed at you, nor assumes the story you want to write.
Let's ask, what could possibly go wrong?
Fu Manchu is a deep and well-developed character, not a garbage bag of every Asian race trope ever
Fu Manchu embodied every yellow-peril fear a white colonialist culture could dream up. It became so bad the US State Department told Hollywood to stop making Fu Manchu pictures – when the US government of the 1930s thinks your stories are too racist, well…
Why didn't they reference a real person like Zuckerb –– oh, because no such person ever existed. Fu Manchu isn't a character, he's a straw man. Hanging a lampshade on the straw man (He's way worse than a Zuckerberg-type) doesn't excuse a garbage bag of harmful tropes.
Admitting the stereotype isn't based on a real thing, doesn't excuse the stereotype. It just admits you knew, and could have done better.
Worse than stereotype: the Stooge
Consider some Straw Man/Stooge fan-favorites:
- Innercity Black men who exist to rob liquor stores in the 1970s
- Latino workers who are lazy, except when they are having violent revolutions which end corruptly.
- Unattractive women... who just happen to be wrong about everything.
- Arabs who denounce all-things European but kidnap white women for some reason.
I'll just call these 'stooges' because 'straw man' implies there's a debate of some sort. Stooges are used when you don't want critical thinking or hesitation. It's shorthand. It works because you can fool some of the people some of the time.
A stooge is designed to provoke our cultural bias. Stooges do work –– for a while. They stop working when the inevitable counter-message emerges. You can't keep performing the same parlor magic when your audience is shouting out how the trick is done.
Fu Manchu was enormously popular, until he became too controversial to touch. Publisher/producers did not grow a conscious, rather it became inconvenient to defend a Fu Manchu project. This should be the take-away: you may find short-term popularity using stooge characters to provoke reader bias, but the backlash can cancel it just as quickly.
the Anti-Stooge, just as bad?
Now consider these 'anti-stooges' – characters that were designed to subvert an over-worn stooge trope:
- Uncle Tom
- Charlie Chan
- The Spice Girls
These characters were designed to be the anti-stooge in their era. They are well-intended constructs that employ the same familiar tropes, but attempt to change the role from stooge to hero.
These characters do not age well. They eventually become the same joke. Their anti-stooge purpose feels insincere, resting on the same stereotypes and tropes they supposedly correct.
Charlie Chan is an international detective, clearly the hero, but buffoons in pidgin English and mangled Confucianisms for humor's sake.
Black'sploitation films feature Black actors in lead roles, but they exist in the same ghetto liquorstore universe of jive-speaking pimps and criminals.
The Spice Girls do not embody feminism (lol) they are just skinny women with different skintones who sing and dance.
I'm not saying these things are un-entertaining today, but they are so divorced from reality as to become ironic camp for the people who appreciate them. For the average person however, they aren't much different to the messaging they tried to subvert.
Despite prominent cast members being Chinese-American and Black, most casual viewers can't get past the MC Charlie Chan being played in yellowface. To the average person, Shaft is just more innercity one-liners said in a blackcent. To the average person, Spice Girls are rather silly, not empowering.
The ultimate is Uncle Tom, so universally despised he's become a pejorative by the people he was constructed to generate sympathy for. It doesn't get worse than that.
All Euro-white culture is the same (a rant).
Now consider my 'European' story where the Orthodox priest 'Queen Medici' of the Warsaw ghetto puts on her bowler hat, serves poison tea and crumpets while goose-stepping in her Nazi uniform and says "Let them eat cake" –– Everyone should be offended, LOL … not so much culturally offended, just having-a-brain offended.
Worse than lazy worldbuilding, this would just be nonsense.
Yet this is exactly how mish-mosh Native Americans are written. Everyone has a teepee and a canoe, tripping over totem poles and two-sprit wolf companions, wearing Ziegfeld feather headdresses all day just for funsies while chatting with their dead ancestors –– conflating radically different cultures, from vastly different geographies, who were often idealogical opposites in belief, custom, and law. Then smearing a couple centuries of colonial ignorance on top.
We don't live in a vacuum. Cultural erasure is worse where there are long-standing colonial narratives. No author can write a story that stands apart from history and culture, or their own biases.
What if it's not Central Asia but the Planet Mongo instead?
Fu Manchu spawned Ming the Merciless – same guy, same costume, same agenda… but less offensive? In my opinion anyway.
The really trope-y aspects become abstracted, while literally staying exactly the same. They both have torture devices, they both have evil daughters, they both have skinny moustaches and silk robes, literally the same guy.
The difference, in my opinion, is that while Fu Manchu is plotting against the British Secret Service in the 20th Century, Ming does not exist in any real world. Every character in Flash Gordon is a trip to the trope salad bar. Mongo needs an uber-villain and Fu Manchu was popular at the time – a decade later Ming might have been Dracula.
I think bad tropes can get 'sanitized' somewhat, but it's still pretty obvious where they came from (Ming, Mongo) and should inform how they are used. Flash Gordon didn't have a lot of time to build characters, and everybody already recognized Fu Manchu. (see also, Nazis in spaaaace). This isn't deep storytelling.
Similar to many American 'menace' tropes having Asian-sounding names, the name for anything sketchy in British fantasy/sci-fi sounds, to my biased ears, like Middle Eastern territories that disagreed about being British colonies. It pulls me out of the story, little voices jump up and say "Das racist!" every time a new witch-prison or desert planet gets mentioned. I'm all, "No! You can't do that! ... That's a real countr...!"
(So I'm rechecking all my planet names – there are problematic names, some are intentional. I'm still debating it.)
the OG: Ruritania
In the wake of 19th Century political shake-ups, lots of fictional countries vaguely situated in Central/Eastern Europe emerged. Ruritania is probably the best example. In-world it's a political hot mess with revolutions every 2 minutes, an addle-brained monarchy, corrupt ministers, and simple peasant folk.
Ruritania spawned endless imitations, until no visit to fictional Eastern Europe was complete without a revolt as a plot-point. These are comedic depictions of Central European culture, but clearly condescending. There was a generation of Caucasians who were under constant proxy 'revolutions' instigated by the Russian Empire (sound familiar?). They probably found this trope less funny, since it was a joke at their expense that belittled their actual situation.
Klockstopia is my favorite spoof name for a fake European country because it tells you not to take any of the story seriously. It pokes fun at the over-used trope not Eastern Europe – it's not funny unless you know there was a lot of nonsense syllabification that came before, but would the average person see a difference…?
I think the best we can do is be aware.
Tropes that are coded still point at where they came from. They can be abstracted, but not entirely rehabilitated. Subverting a trope actually adds to it. It doesn't fix the problem.
Inventing fictional countries that stand for real places is going to involve some level of 'ching-chong' syllabification (which may offend readers)..., or a lot of worldbuild-y research (which may derail your idea). It's good to indicate which type of story this will be. Readers are generous if the story-tone is correct.
Ruritania was popular in its day. I'm too far removed from the era, I can't tell if it sounded derogatory like 'Muckiyuckistan', or if it was intended to sound plausible (I'm guessing satire, from the context of the stories).
The 'frame challenge' advice might be to not write a fictional 'country' but a fictional person (a family) who moved around these areas their whole lives picking up traditions and experiences, while also clearly being individuals who have character development and some agency. Setting up some idealogical contrasts within the immediate characters will help to prevent them all becoming ambiguously brown.