That's not the first time something like this happened. The japanese version pokemon sapphire was 64mb while the english version was 128mb. Things like this can't be helped so you'll have to deal with it.
well I dont know about English -> German but most definitly Japanese -> Englis results in alot of size diffrence.
A single Japanese charector could represent what it takes a whole sentence in English to say.
Games programed for the Japanese speaking language general are designed around the space requirments of that language. This is why many Japanese RPG's translated to English have heavely abriviated item names and the likes. Also some times theres not enough room in the diolog boxes to fit the English text so they either re word the english to fit the limited space (this generaly results in a crusy translation with tons of improper broken english) or they have to expand the ROM to the next valid size to add more text boxes.
Note the Japanese FF4 SNES ROM is smaller then the J2e translation of the same ROM. J2e opted to expand the ROM size to make more room for a cleaner translation.