Two sources. First, I heard all of this and more direct from the elders. But of course you won't believe this. Second, and more detailed is a book written by a Kenyan Oromo from River Tana on the history of this region. His sources are the elderly freed Wardey slaves, elderly Orma men, and Daarood reer Waamo old men, colonials sources etc. Very well researched. The book is called Herder Warfare in East Africa, Gufu Oba. He has a whole chapter on the Daarood conquest of Waamo. He also takes about the history of Waamo before the conquest and afterwards. It's a very good book and a must read.
Unfortunately because the Kacaan didn't give any attention to the history and culture of Waamo, most Somalis are ignorant of this history. This is crazy when you realise the Daarood Conquest of Waamo was the single greatest achievement of the Somali race after the Conquest of Abyssinia. Period. There should be statues of Suldan Abdi Ibrahim in Xamar today. He was the commander of the combined Daarood forces. He is buried in Mwingi today at the foothills of a mountain called Buur Belaayo where he was killed in battle. Also Ahmed Magan and others should be celebrates heroes. Sadly, all the poetry from those battles haven't been recorded and are probably lost.