Yes it can. I would say that the German national identity realy developed in the 19th, maybe late 18th century. Before that, it coul d easily be possible for people we now consider German, to develop its own identity, just like the Dutch, Flemish, Swiss, Luxemburgians, Austrians and the Lichtensteiners (and Walloons and Chzech) did.
A different ending of the 30 year war could do it. Or an earlier end of the HRE. Or a Prussia that focused more on Poland, or a Prussia that gotleft out of the unification, like Austria. Or Bavaria that got left out of the unification. Or Hanover that remains in a personal union with Britain. etc. There are many ways.