To clarify;

Erde vs a tank (a tank as in, the definition of a tank. Not a hovertank; A tank. Ground-based) = The result is a -guaranteed- victory to Erde. No matter fucking what. Yes, even then. - Therefore, not a dick waving. It's not an accomplishment. It's like me saying I could easily defeat a cockroach in single combat. It's a given. A fact.

Garrett vs Erde = An uncertainty - Not a given. Not a fact. Saying either could easily defeat the other is dick waving.

ASTA - Being limited to ground-only movement, without even the capability to jump, and with no other mode of movement, means that -yes-, Erde automatically wins, because there is -no- way to dodge ANY of his attacks.