@Naofumi, let me explain.
Vedic Sanskrit turned into various 'accents'; quite obviously they resembled each other, having originated from the same stock. Equally obviously, nobody set out to speak differently from people three or four generations, or fifty generations before; they found themselves speaking in different accents, later dialects, later languages, without having wished it. It was academicians, not necessarily European academicians, but our own 'native' academicians who noticed that people were speaking a variety of very similar dialects, even languages, and, for their own convenience, clubbed these together and put a label to that clubbed mass. Nobody set out to speak Suraseni Prakrit; it was classifiers who came much later who grouped all those western dialects turning into languages and called them Suraseni Prakrit.
So, don't be too taken in by labels. Labels were invented by people who got headaches looking at the mess of material lying around.