Fantasy Genocides and how should my magical system tie into it (Repost)

So Im starting a new world setting, and this one is perhaps a more fantasy High Fleet (So desert world, most humans live in oases that vary in size, and fantasy/sci-fi airships). So I plan on having genocides and racism and such in the setiing, i plan on having two ways of approaching this: I could, 1. Have different "humans", like for example, underground humans, surface humans and floating island humans; or 2. I could just have different cultures, different skin colors, different regions and such... Which one would be a better approach to such a world in your opinion (I'm mostly doing option 2 as per advice from this subs)

Edit 2: On the topic of racism, I am from Hong Kong, and thus in extent, Asia. As my culture and society is mainly homogeneous (Made mostly of Asian), when I say racism, I meant Asian racism, which while to some might mean discrimination. Asian racism for example would be like East Asians being racist to SEA Asians, mainly due to how developed the country is, the perceived overall lower social status, usual position of lower labour job, and the slight differences in skin color.

The skin colors within this world: Most humans would have dark-tan skin colors due to the high UV that would be present with the hit amounts of sun light. Then there would be lighter/yellow tones of skin colors of few types of people who live on mountains and cliffs, which provide more clouds, shade and such. There are also people who live on floating platforms (which I have not decided if these are a recent invention or a long existing one), which I imagine would have either a mix of who comes to stay on these platforms (I have also not decided if they would move or not…) or of simply a darker tone then all others due to high UV and such, if I choose the latter, I’d imagine that they would get the most amount of racism of all the races in this world. There would perhaps at most be a race of incredibly rare pale white humans who would have either lived in caves or in deep cliffs or valleys without direct sunlight. (Fake vampires! lol) Or perhaps they will just be the royalty of the top empires? Who stay indoors more of the time i assume? (the racism hierarchy/gradient could be the lighter/fairer you are in skin color, the higher you are? Or perhaps yellow/asian skin color is of the highest gradient as european pale white is too hard to achieve in such a world.)

Edit 1: I am back with more ideas/context that i didn't add and will now add them to this post, so this is like a desert world as stated before, but there are monsters roam the deserts, making large scale land transport impossible (tho they don't attack oases and such). The main form of transportation is through airships, and this is a part that somewhat bothers me. So like there would be many ways of powering/making these ships float: Floating part: Air magic, crystals, or a combo of both; Powering part: Magic, Internal Combustion, Magic assisted combustion, or a hybrid of all three.

These lead to a somewhat core choice regarding the path of which I will take with this world

How magic comes to be in humans, so I've came up with three types:

1. Magic is hereditary, this would creating a upper/ruling class of mages and such. However, I do have to figure out why they would work and such but that is up to me.  2. Magic is racial/regional, this somewhat ties into the racial and genocide side of the world that I will focus on (Side note, this world will focus on politics, trading, racism, wars and AIRSHIPS), so mages and such would mainly come from some? specific racial groups of people or some specific locations would have a higher chance of mage birth. This ties into racism as, any empire/large enough governing body would decide to enslave/colonize them, this would also create a power imbalance as to why they would follow but than again for me to work on. (I know this is the longest but please also consider other options)  3. Magic is random, this is perhaps the most easy of them all, with who controls the mage academies being the strongest. This would lead to world wide magic detection at certain age and also conscription? or taking away of children due to them now being strategic resources.  4. Or I could do a mixture of them all, like some families have it more, a few races have it more (although they would only have air magic), and there are random births. (I will be doing this one as of now)

TLDR: Monsters roam the desert so airships are the only way to move around. I am deciding if magic (that powers these airhips) is a birthright for upper class/families, a racial trait used to justify colonization and slavery, or a random lottery where some states conscripts kids as strategic resources and such.

Btw I will also still do regular racism and genocide on top of these. because Starsector, Highfleet, and many more games have had a profound impact on my view of interesting things...