I start from the hypothesis that it is not possible to assume an "older more diffuse state", as von Polenz (199) puts it, for the Early New High German period but rather a tolerance of variations which is characterised by a co-existence of various possibilities for inflection, indication and determination.
My hypothesis is that, since the 17th century, functional means have been restricted rather than extended.
In language history the 18th century is traditionally depicted as the period in which the New High German written language was standardised and codified.
The end of the Early New High German linguistic age is accompanied by the abandonment of doublet forms or variations, a process which asserted itself in the 18th century and is fixed by such grammarians as Gottsched and Adelung.
Traditional history of language more or less explicitly adopts the point of view that language developed as a continuum with its origins in the east-central High German variety as embellished and consolidated by the Reformation, the spread of book printing, officialese and the influence of belles lettres as well as grammatical description.