Actually, the first printed German bible came out in 1466 - the Mentel Bible, which went through 18 editions until Luther's superseded it in 1522.
Dozens more versions appeared in the decades after.
Luther's claim to fame was that his captured the hearts of so many of his countrymen, becoming interwoven into the language itself and its idioms.
You are entirely correct. In fact, just in English it is hard to count the number of translations and versions. Some sites show how these different versions differ:
http://www.av1611.org/biblecom.html http://www.cob-net.org/compare.htm http://www.tyndale.cam.ac.uk/scriptures/ http://www.geocities.com/bible_translation/compare.htm
Because of these differences and contradictions, any claim as to being "the Word of God" rather silly.