Every historical indication intimates the north Germans were more powerful than Egypt or Rome. Read the Oera Linda and it fits they were the Sea Peoples.
Consider facts like these
A. Germanicus, a Roman Emperor named as conquering Germany, sailed the largest fleet the Romans had ever built, over 1k ships, up the Rhine. He returned with few survivors. Officially, the fleet was destroyed by a bad storm. The city then held a triumph for him and said he conquered Germany.
B. Rome expanded far to the East, West, and South but didn't get far North.
C. From Rome's earliest ascendancy, according to Julius Caesar's own war journal, battles were won because of the assistance of German nobility on horseback.
D. At no time in its' history was Rome able to overcome Germany tribes by its' own force of arms. It always relied on paying tribute to some tribes to protect it from others.
E. When Germans stopped working for Rome and turned against it instead Rome was sacked.
F. When Europe needed defended against Attila it was a German Chieftan who led the confederation with Roman allies as junior members.
G. Runic writing predates Greek and Roman writing systems yet we are to believe for millenia northern europeans never used the language they invented but were illiterate.
H. The majority of records were destroyed during the judaic apocalypse of Christianity and Islam destroying civilization in the west and the east.
I. Monks would introduce books, possibly of their own authoring, as ancient Greek or Roman texts, to give them scholarly traction in the same way royalty fabricated lineages from past leaders for legitimacy.