Ethiopian;s have made everyone believe that they were the only precolonial state in East Africa. 
In fact, Abyssinia was not even the most powerful state in East Africa as that title goes to the Imamate of Adal which conquered all of Abyssinia that was east of Lake Tana.   
What you cannot argue with is the fact that Ethiopia will always have hegemony over Somalia, as long as they control the Bale Mountains, Somalia's source of water. The Ethiopians also want to divide and rule Somalia directly, which is why the writer proposes a free trade zone of sorts where Ethiopia gets free ports on the Indian Ocean. How can a country of 13 million form any sort of equal partnership with one that is 100 million? Somalis must navigate this problem of a neighbor who controls our water and has malign ambitions. Unfortunately, federalism will make this impossible, as you need a strong centralized state to deal with a threat of this magnitude.