If the Tigrian Came from ጤግሮስና ኤፍራጠስ ወንዝ the galla came from igala people of nigeria. After all most evil and scam come from Nigeria!
Proof of galla nigerian ancestory:
We even have galla goats in northern kenya, nice and milk producing goats owned by norther kenyan farmers called galla.
Then why is it a taboo to call a galla person and goat “galla”?