I didn't deny that ,I mentioned that farming was being practiced on the coast aswell. Also afgooye was providing for mogadishu mainly not whole of banadir coast.The source you cited 'the origins and development of Mogadishu' argues the hinterland (Afgooye) played a crucial role in the development of the Benadir. You can't pick and choose parts from the text to support your claims, while ignoring others.
It's not clarified who the population in Xamar Jajab was, how extensive the supposed agriculture, time frame ect.
No, you just omitted key details. We're discussing Mogadishu here.I didn't deny that ,I mentioned that farming was being practiced on the coast aswell. Also afgooye was providing for mogadishu mainly not whole of banadir coast.
The people who resided in modern day xamar jajab are definitely known since people of xamar kept their history well recorded .I'm sure it's mentioned in one of the qadhi records, there's also plenty of graves there with names engraved on them.