Why would you feel bad for people that have their own country? Black Americans are a marginalized minority within America, and relative to the rest of the Caribbean Dominicans are doing fine. Also, Sudanese people identify as their tribe more so than Arab or non-Arab (even Nubians and Beja identify as tribe followed by Sudanese rather than their ethnicity), and Darfur itself has many Arab tribes (some of them look just like Khaleejis/pure bedouins too). Sudanese people are very prideful so it's really not as deep as you're trying to make it. Lastly, some tribes did "lose" their language but language shifts happened a lot throughout history. Sudanese Arabic is a lingua-franca and has unified the country (along with Islam) despite previous linguistic and religious divides during medieval times when the country was constantly at a state of civil war.I feel sad for the sudanese. They are in someways the equivalent of black people in the americas, they remind me of Dominicans actually. Dominicans are mostly black looking of mixed but lost their language and culture and only speak Spanish. They deny being black but they realize how black they are when they travel to other latin countries. It's the same with Sudan, they lost their language to adopt arabness but they face abuse by other arabs.
Some Arab sudanese call darfurians and South sudanese " abid" but the truth is that darfurians, Dinkas and nuers are not slaves to a foreign culture, they know who they are and they know their language.