If you look at Somalis, they can range from light skin with small noses/soft hair to darkskin with an afro and a bigger nose. Lip sizes also greatly vary.
Look at any other homogenous ethnic group: eg the most homogenous group in the world, Koreans. They all have relatively the same skin colour, hair texture and general features.
Even if you look at diverse African countries and tribes (Ghanaians, Nigerians etc) they all relatively share the same features.
Yes there are some identifiable features, but Somalis are physically very diverse which is strange for such a homogenous group.
There are many bantu & yemeni looking ethnic Somalis.