I don’t believe they ever replaced the legions destroyed at the Teutoberg forest debacle.
“VARUS! GIVE ME BACK MY LEGIONS!”-AUGUSTUS
Yeah, Hermann the German & Co. nailed them Romans to trees.
If they’d been smart they would have surrendered: they could have had fabric clothing, sanitary facilities, concrete aquaducts, civil law—and wouldn’t sound like they were gargling when they talked.