Thanks for the reply! As a student of Russian, my impression differs a bit - the language seems to shorthand "to
be", rather than go without, much like a beginning e-prime speaker saying "My name - John", thinking they had figured out a cheat. In fact, Russian has exactly this construction:
I - student.
You - very pretty.
They - capitalist spies.
I don't wonder, rather than evolving from using to-be to not using to-be, that they instead acquired the construction at some point, but not the verb. All hierarchical civilizations need a way of naming and labeling specialists, such as masons, carpenters, bureaucrats, priests, kings, advisors, etc. If you don't have "to
be", you can't label someone. You can only describe their activity, which in fact indigenous languages seem to consistently resort to, in order to "name" or label someone. The Iroquois statesman "Cornplanter", translated more accurately from the original language, would sound like "He plants Corn". You can find this style of naming popping up over and over among non-civilizational cultures, and intuitively it may already ring bells for you, when you think of native naming practices.