Oromos in hargeisa in the 1500s? How did they go past the Ogadens, Cisse, Isaaq? You know Somalis were still crazy strong? How can some Oromos with horses and a wooden stick compare to Somalis with Arabian horses, iron swords, spears and ottoman guns? Oromos were in the stone age while Somalis were in the late middle ages
Wallahi my advice would be to not bother arguing with them it's a wast of time, we have better things to do. We oughta follow what our lord said in the quran al-karim instead.
أَعُوْذُ بِاللّٰهِ مِنَ الشَّيْطٰانِ الرَّجِيْمِ
بِسْمِ ٱللّٰهِ ٱلرَّحْمٰنِ ٱلرَّحِيمِ
وَعِبَادُ الرَّحْمَنِ الَّذِينَ يَمْشُونَ عَلَى الْأَرْضِ هَوْنًا وَإِذَا خَاطَبَهُمُ الْجَاهِلُونَ قَالُوا سَلَامًا
The worshipers of the Merciful are those who walk humbly on the earth, and when the ignorant address them say: 'Peace.
وَالَّذِينَ لَا يَشْهَدُونَ الزُّورَ وَإِذَا مَرُّوا بِاللَّغْوِ مَرُّوا كِرَامًا
And [they are] those who do not testify to falsehood, and when they pass near ill speech or blabber, they pass by with dignity.