I didn't say that it was a dichotomy, actually I tend to think of the space as roughly split into three: lists, arrays and annotated/sorted trees. Lists and ar

I didn't say that it was a dichotomy, actually I tend to think of the space as roughly split into three: lists, arrays and annotated/sorted trees. Lists and arrays are really common though, so I think it makes sense to make it easy to refer to them using short words.