Sorry to break it to you but the name of the author, Gitura Mwaura is 100% a Kikuyu name. Very likely the writter of the article is a Kenyan citizen. I wonder why the Rwanda govt would give a Kenyan geopolitics writer a platform on their state newspaper.
Anyway, the author of the article is not totally wrong though. If Amisom left today the govt in Mogadishu would eventually fall after some time. Of course alshabab would never be able to capture the whole country as the writer claims but they would take the capital and control large areas in the south.