In Mesopotamian history, were Sumerians and Akkadians understood as being separate nations?
A text I find really interesting for the era is Shulgi B, where the languages he lists are Elamite, Sumerian, Meluhhan, Amorite and Subartian. Notably, Akkadian is not mentioned at all, which raises the question of whether the label at the time would've applied to a national identity, to the specific dynasty of Sargon, or to the city of Agade. Moreover, would the people we know as Akkadians have been considered black headed people during the EDP?
Before the time of Sargon, was there any label that would've refered to the Semitic peoples north of Nippur? As far as I understand, they seem to have been culturally very similar to the Sumerians, as opposed to the situation at Ebla (where the temple was a much weaker institution). Then, where did the title of King of Sumer and Akkad come from? By the time it appeared there had to be at least some notion of there being two distinct societies which had been united, but I'm not sure that framing would've made a lot of sense centuries prior.
Of course, the case of the Akkadians is a very strong contrast to how the Amorites were viewed in Mesopotamian history. The narrative of Hammurabi's dynasty definitely did rely on them being entrusted with divine kingship, expressed in the patronage of local Mesopotamian institutions, but at least these Mesopotamian institutions did exist in contrast to the tribal style of leadership seen to the West. I'm not sure any such dynamic could've applied to the earlier Akkadians outside the ruling dynasty (which brings us back to the question: was anyone outside the ruling dynasty considered to be an Akkadian?)
One last related question regards how later Mesopotamians would've understood the period of coexistence between both populations. I doubt the people of the Iron Age would've considered themselves to have been descended from the people who replaced the Sumerians, but did that mean they believed Sumerian people disappeared at some point? This even brings up the question of metalinguistical awareness: could they have imagined Sumerian having once been a living vernacular? I'm aware of the narrative of the confusion of tongues, but I'm less certain that was the explanation they would've given for why people no longer spoke Sumerian.