Do you think the whole peaceful Naathi religion is based on Buddhism? I definitely got the whole pacifist Asian vibe, not very original IMO. Also, what do you think about the religion of the Unsullied? We don't get much about it, but i think it's interesting that the Unsullied, despite being from vastly different places, adopted a common goddess.
It's a possibility that that's where GRRM took inspiration from. I know that there are some people who read Missandei (and the Naathi people) as being analogous to Asian peoples (of course not a one to one comparison, because they're not developed enough for us to really know which distinctive group they might be closest to).
The Unsullied goddess seems to be borne from a common experience of being enslaved and forced into this specific way of life. It's interesting that only Unsullied know the name of the goddess and once you're initiated as such then you're able to know their religion. As someone mentioned, it's interesting to think about whether the Great Masters forced this religion on them to maintain discipline (since their goddess is called Lady of Spears and Bride of Battle as opposed to something that doesn't glorify their position as super soldiers) or whether they chose it for themselves. I don't think it's actually said in the books, but I could be wrong.