See that's the problem statements don't really count when going cross universe when there's no feats to back them up. How many times has freziza or vegeta claimed to be the "most powerful in the universe" when they both knew beerus existed? The canon of dbz in particular is constantly guilty of hyperbole. Oh and I wasn't gonna mention it, but if this is "canon" Goku we're talking about, he wouldn't kill any innocents and would probably spare most of those that tried to kill him.