They actually don't need to do cleaning and redrawing that's mostly unofficial/illegal scan team since official team gets the raw images directly from the artist/author without Korean typesetting yet, so funny enough unofficial scan teams do more work in less time than official. But they also have to go through an approval process which scan teams don't so that could hinder their speed quite a bit, and since this is a company they probably have other works to translate at the same time! and while I wish webnovel companies were known for treating their employees well they sadly aren't so it could also be poor working conditions causing the translators to get sick (similarly to how artists often get sick)
I hate that the English translation is sooo behind it’s actually sad…. Someone pls tell me why English translation is always behind when I know that the Korean raws are way ahead ╥﹏╥ besides the fact the Korean language needs to be translated to English ╥﹏╥