These lines written via game_text entity and you can't translate them. I know a way how to do this, but this requiring map edits. Just open every map in notepad (or notepad++, it works faster) and look for "game_text" lines. You will find "message" line somewhere near "game_text". Then replace first symbol in every message with "#", for example : "Hen Mazolski" - "#en Mazolski"
Then create "en Mazolski" "Hen Mazolski" line in nh2_english and translated one in nh2_language.
It's little bit odd way, but if you really want them translated, it shall work. With additional `200 mb.