When a song is translated into another language, some words and sentences cannot be translated directly, because they have to fit into the rhyme scheme, rythm or simply the stylistically suitable choice of words. While English and German are very similar in lenght of words, etc., but Irish is much different from either language. I assume the song was translated from German into Irish, which could make it different from the translation into English. There might also be (a) translation(s) based on the English translation, so that could make differences again.
By the way, while the language is German, it is an Austrian song. But many countries claim it as their own, really. People think it's German, American, anything really as long it's theirs