They are not Middle-Eastern
Davos, as a character, is from K'un-Lun, originally, as is his father, Lei Kung, a Tibetan region within China.
If we look at Hoon Lee's portrayal of Lei Kung, we see a faithful representation (Asian-American playing the role of an East-Asian character):
Lei Kung's son, Davos, played by British-Indian actor Sacha Dhawan, isn't necessarily an inaccurate portrayal:
Consider that we don't know what the ethnicity of Davos' mother (in the Netflix show Iron Fist) - a child's genetic phenotypes are the result of a distribution from both parents.
As for Bakuto, according to comicbook.com:
[in the comics,] Bakuto was The Hand's Daimyo of South America; when Daredevil took over as leader of The Hand in the early 2010s, Bakuto was one of the leaders at a Hand summit Daredevil held.
—Iron Fist: Who is Bakuto?, comicbook.com
Though his ethnicity isn't specifically and explicitly stated in the comics, he is most probably Japanese, and his xenophobia for non-Japanese characters, like being outraged at the "American", Daredevil, being in charge of the Hand, is brought up in the comics, so it does seem to be key to his character (also his character design and name is heavily inspired by the Yakuza).
However, Ramón Rodríguez's portrayal of Bakuto, ethnically, seems to be irrelevant with what his role requires, in Netflix/Marvel TV's interpretation so his Puerto Rican background is practically irrelevant. He doesn't make any references to Japanese culture, in the same way his comic-book counterpart does.
It's also worth noting that there isn't such thing as "Middle-Eastern" ethnicity, as the so called "Middle-East" covers a large array of countries and cultures and ethnic backgrounds that can hardly be generalized under one term, when trying to describe an ethnicity. Some may take offense with this generalisation, not that I did.