Slightly off topic but how exactly did the Adal sultanate end? I believe it was dissolved duo to the Oromo migrations and was succeeded by the Harar emirate but according to wikipedia, the last member of the Walashma dynasty was killed by Ethiopians but I don't trust wikipedia when it comes to Somalo history
Adal Sultanate - Wikipedia
en.wikipedia.org
It was the ensuing upheaval of the 16th century. When Imam Gurey came to power he pretty much led a revolutionary military coup and rendered the Walashma Sultans into mere figure head kings.
When he died unexpectedly without creating a mechanism for succession , the power split into two political factions , one based in Harar by Emir Nur and the other on based in Awsa by Mohamed Gasa. That's basically how it dissolved politically, it caused a civil war and fighting to fill the power vaccum.
2nd reason was economical one which was due the trade blockage blockage and disturbance in the Indian ocean and red sea by the Portuguese. The Oromo migrations created disturbance in the interior trade routes and decimated the lands.
This is all covered by the internal Arabic Manuscripts in the periods after the Conquest of Abyssinia. You should go to directly to the primary sources if you don't trust any other.