In adding (or editing) works, editions, EG et al. we should only need to set the language once, and then, if the language of title != language of text of the book we can have a flag or special tickbox to set this.

Another way of simplifying this is: have the 10/5 most often used languages show first in the list.
alternatively, have the previously chosen 3-5 languages first in the list (like recently selected entities in MB)