"Strictly speaking" of proto-fascists as "individuals or movements politically promotive of fascism, both through explicit endorsement of fascist ideals and/or intentional development of conditions favorable to fascism." You could speak of them with another definition, I guess.

Germans have been, as a whole, a near-inherently proto-fascist ethnic group since the establishment of the German Empire, and their proto-fascist tendencies were only furthered from above by Bismark's corporatist conservatism and Wilhelm II's Weltpolitik. (It might be helpful to compare them to other near-inherently reactionary ethnic groups like Ingrian Finns, Estonians, Latvians, Lithuanians, Poles, Jews, Volga Germans, Tatars, Chechens, Kurds, etc.)

80% is frankly a generous figure. The Reichstag unanimously supported the Kaiser in WWI, which (in Germany's case) was THE textbook war of proto-fascist aggression. There were some dissenters as the war dragged on, but for the most part, Germans were fine with the development of the OHL dictatorship, which was also the most prominent/powerful proto-fascist regime in history. By the '30s, every mainstream political party in Germany was proto-fascist: The KPD, with their promotion of Third Period "let's enable fascists" politics; the SPD, who collaborated with the proto-fascist Freikorps and and abandoned class struggle politics in favor of corporatist ones; and the rest of the parties for obvious reasons.

In Germans' defense, nearly every ethnic group has historically been proto-fascist. The Dutch, pre-Empire Bavarians, and maybe the Australians (not a real ethnic group but to the extent they are one) are pretty much the sole exceptions from any of the remotely relevant groups (racism isn't necessarily proto-fascist).