You're obviously projecting about making up claims because you know you cannot actually hold your belief in agro-Levantine supremacy, which by the way, the distantly ancient Levantines were not even Semitic. That would be the Akkadians, who came well after the Sumerians and have recently been pushed up earlier several centuries (about six centuries).

>Irrigation is not required for farming
Nonsense. Irrigation is the marker of organized farming. Without that infrastructure, there is simply no evidence for the organized cultivation of crops en mass. Evidence for such exists in India going back to the 4th millennium and across the steppe in the 3rd millennium. The Levant does not have any evidence of such until the 1st millennium BC. Very late stage. Practically barbaric by global standards. I half expect Levantines to be running around in wash rags with bone piercings in their noses shouting "ooga-booga!".

>Mesopotamia required irrigation because it was a swamp
It oscillated over time. The areas of irrigation cover the mud flats to the south closer to the coats up to the near desertified areas of Iraq and Syria.