Don't hassle with the language files. Imo they aren't worth to process with wemtool (just ~15mb per language if you skip all files below 100kb).
You can extract the WEM files with this tool I guess (I use another tool without 2GB limitation)
https://www.fileforums.com/showpost....6&postcount=82
A bit messy but if you get any errors with that 2GB file limitation, just search for the first riff wavefmt stream somewhere in mid-file offset, then split this file into two halfs and use the extractor if you don't have other tools by hand. Like I said this is a bit messy but should work as a workaround. After split and extracting WEM files, erase WEM files with xtool erase command. Afterwards just merge the two files back into one file, then decode back WEM files afterwards with xtool. The rest is up to you.
If I remember correctly the total save with processed WEM files is about 200-250MB in total without language files (input ~1.27 GB).