I'm all for Germanic Nationalism; I get yelled at for it all the time; but there are so many alliances already. And the same goals are defined aswell in those alliances.
The Germanic Empire and the Norden Verein are two larger ones. I'm a founder of the Volksleitung, which turned into the Nordreich. The NoR was huge, but it had many nazis in it. Trust me, if you make a German alliance, they will join. They always do. And it is very hard to find the good ones.