I understand why you may have come to this conclusion, but this is a pretty misguided take at best and making the problem worse at worst. The problem with the al Ghuls is not that they are villainous, powerful, or dangerous, it is that they are flattened and unchanging, unable to be given evolution, depth, or an interiority independent of a western viewer who brings them to life with his viewership. This, not base negativity, is the foundation of Said's Orientalism as scholarly critique:

In a sense the limitations of Orientalism are, as I said earlier, the limitations that follow upon disregarding, essentializing, denuding the humanity of another culture, people, or geographical region. But Orientalism has taken a further step than that: it views the Orient as something whose existence is not only displayed but has remained fixed in time and place for the West. [...] The West is the actor, the Orient a passive reactor. The West is the spectator, the judge and jury, of every facet of Oriental behavior. [...] The Oriental is given as fixed, stable, in need of investigation, in need even of knowledge about himself. No dialectic is either desired or allowed. There is a source of information (the Oriental) and a source of knowledge (the Orientalist), in short, a writer and a subject matter otherwise inert. The relationship between the two is radically a matter of power [...]

Orientalism happens in the distortion, generalisation, and instrumentalisation of that material for a Western gaze, not in the mere fact of a Western person writing about Asia or Asians at all, even villainous ones. There is obviously a certain amount of it that is inescapable; Orientalism in the pop culture is derived from the authority of scholarship which, uh, DC Comics will very obviously be unable to hold a candle to. You will never get revolutionary or liberatory writing from this company or characters. Nor can these characters ever be detached from their history or the history of the man who created them or the history of their inspirations and their creators, and so on and so forth. So that's the baseline.

But even working within that somewhat defeatist attitude, I think the above proposal in a reboot is far bleaker and dehumanizing than my own realism-ideal scenario, which is as simple as Make The Al Ghuls Complex People With Their Own Emotional Histories & Perspectives. Ra's can dangle Bruce chained up above a pit of lava (see also: the eroticism of Ra's al Ghul) for all I care as long as I understand how and why we got there and Ra's doesn't feel like a caricature. I am a reader; I like danger and mystique and power in my fiction! Danger and mystique and power is not the enemy, essentialisation is! The Asian man can be a despot because he individually is a despot, not because Asians are predisposed to despotism; to duck this truth due to a fear of the difficulties of clarification makes it sound like you're afraid of the ghost of Karl Wittfogel. The Orientalist levers we see in the depiction of the al Ghuls are writing choices that are independently fixable.

To take the League of Assassins and give it to Henri Ducard or David Cain or Slade Wilson or whomever has not de-Orientalised the story, but rather it states that only a European hand can safely (or rather, without discomfort) hold that power, while the Asians get flattened (again!) and stripped of their power for the sake of narrative rehabilitation (and again, comfort on the part of the audience). Not to mention that without fundamentally changing core components of what the League is but now denying it the possibility of evolution and depth in accordance with its leader, it still has its roots in Orientalist exoticism. The Orient still supplies the danger and mystery, it's just been outsourced to a white proxy so the reader doesn't have to feel bad about who's wielding it.

The bigger issue than the League, though, to me, is the framing of what is left for the al Ghuls. Asianness, Arabness, and the Oriental is only allowed clemency and legitimacy when they have been de-fanged and divested of, to be frank, anything interesting in their story. To deny Ra's his ideology and to deny Talia of her central conflict--what is left? "A completely ordinary civilian family of Arab immigrants"--why? Why is the only safe way to depict brown people smallness, innocence, mundanity? Why are they immigrants; is it so inconceivable that world traveler, billionaire, and superhero Bruce Wayne could fall in love in Lebanon, Palestine, Jordan, Iraq, Kuwait? Don't think that this is any different from the idea that the West can 'tame' and 'civilize' through its influence.

Why does ambition and grandeur and mysticism taint Asians so uniquely and thoroughly that we have to throw the baby out with the bathwater, while, say, the innate conservatism of Bruce's character as billionaire patriarch and hero stamping out a 'criminal parasite', while an obvious myth that flatters Anglo-American capital's right to rule against a failing state and assertion of moral order, allowed to be complicated, subverted, and redefined? Denying the al Ghuls that same grace is a failing, not a fix. It just shuffles the discomfort and asserts a kind of condescension, a lack of belief that a reader can identify the distinction between "Arab characters can be complex, powerful, and even antagonistic" and "Arabs are a sinister race".

In short:

The nostaligia-fueled version of Robin Dick that exists in his head

Jason Todd's corpse