The research has shown that they have under 3% horn african y-haplogroup and share kinship genetic to hutus. Beside that do you know the belgians are the ones who in-forced the racial divide between Hutus and Tutusis after it being just a social class divide?, one of the main ways to be classified as Tutsi is to have more than 10 cows, be over 6 feet and have the facial features. So if you took into consideration that Tutsis and Hutus intermarried a lot, you can say that some hutus with more than 10 cows, or having facial features as horners or being tall made them to be classified as tutsis. Belgian laws banned the intermarrying between the groups to continue after the racial divide.If they're fathers are Bantu how did they maintain their Cushitic features?
If you take Germany's population and divide them based on hair and eye colors and made a law prohibiting intermarriage, you will end up with two group people from the same ethnic group having distinct look.