By the way, I know I got off subject, but that was an interesting article. It sounded like they were in a state of nearly constant civil war between entities that should have been friends and allies...
The city-states would occasionally get more prosperous than their neighbors and would march on out and couquer as many as they could. This often happened when another city-state had some kind of setback such as a military defeat, dynastic crisis, that kind of thing. Lagash, which I'm sure most had never heard of, went through a boom phase, lots of public building construction, prosperity -- then got pulverized shortly after Gudea's time, and pretty much wiped out. The large cuneiform archive (clay tablets) of Mari was preserved by the inferno that consumed the city when it was destroyed by a none-too-neighborly neighbor. But that ws a huge break for modern scholars, so, too bad, so sad. :^)