Never in Ethiopia's history have they offered Somalis peace, they have always seen us as Ethiopians that got away and if they wanted peace with Somalis they would have left Western Somalia alone, not ask the British for Hiran and Zeila as well.
Oromo have already shown they cant be friendly without control the Government, fighting over land with every region. Forcing Somalis to not call dire Dawa their capital. so what makes you think after Tigray rule and Amharic rule, that Oromo rule would be better. They would continue their expansionist policy but now with state control.