Unacceptable. Everyone should know that the adaptations, don't always follow the original content in script or story. The only way to figure that out is to translate it yourself. Using the names or figures of speech from the other version is acceptable, for the translation consistences.

First of all, there is an assumption that the anime text follows the manga text. If it doesn't, then the answer is none of the given options, it is rather "unacceptable because the scanlator is too incompetent for this biz".

If the lines align exactly, then the way the poll is worded, I have to go with "unacceptable". However, if there were a choice "acceptable, as long as you credit the anime translator rather than yourself", I'd go with that. In short, plagiarism is generally frowned upon, so cite your sources correctly.

As a former English/Japanese-to-German fansubber, I once translated an anime (I think it was Witchcraft Works), where a passage was utterly incomprehensible to me, so I referred to the (English) scanlations to figure out what's going on. It didn't help all that much, but I personally find using the counterpart's translation perfectly acceptable. Copy-paste is a big no-no, and probably wouldn't work out most of the time anyway, but using it as reference... sure, why not. Especially if the language translated to is entirely different from the one "used".

This poll doesn't have nearly enough options. What I pick is: Unacceptable, because this automatic assumption that the anime script would correspond with the manga script is idiotic, and these kind of "scanlations" could only come from someone who doesn't know a word of Japanese but is pretending otherwise, the worst kind of "translator" out there.

Unacceptable, but for another reason. Not that masquerading someone else's work as your own is fine either. Most of the dialogue in even direct adaptations isn´t word for word and what would you do if chunks are missing? This week´s JoJo skipped the 3 pages that showed how Passione got on the airport for example. There is nothing wrong with looking up how another translator solved a peculiar issue, at least if fans do this, but going anime to manga (or the other way) is still kinda dicey.

I know of all the abysmal machine translations but that is mostly an issue with web-comics and web LNs. Are maniacs currently using the poll´s method to translate manga though?

Edit: Option 1 doesn´t make much sense. How are the translators supposed to know that the full dialogue they took from the subs is accurate if they lack the ability to translate the original dialogue themselves? These options are weird.

There's a lot of factors here. Does the scanlator have permission to copy the fansub in this case? Are they double checking that the translation is still valid for the manga? If the fansubbers are okay with it, and the dialogue is the same, I don't see an issue with them saving time by using the pre-existing translation, especially if it's a manga/anime that has a lot of tricky-to-translate phrases.

I put perfectly acceptable, as long as it's accurate

Other commenters seem to be completely missing "as long as it's accurate" because they're interjecting with idiotic things like "BUT WHAT IF IT'S NOT ACCURATE?!" Obviously "as long as it's accurate" means "as long as the translation is still accurate in the adaptation", not "as long as the original was accurate for its medium".

But I have another stipulation: the person must be credited by default (they can obviously ask to be un-credited) for it to remain "perfectly acceptable". Crediting yourself is the worst, and crediting no one is only okay if they ask to not be credited.

Things get a lot sketchier when you're using, say, an official viz media translation of a manga to fansub an anime, since then you're stealing something of actual monetary value (their translation). But for an unofficial translation, I don't believe a translator has some kind of legal ownership of it or any "unofficial version of legal ownership", either. So you don't have to "ask their permission" to use their translation, but you should reach out to them and say "hey, I'm going to use this translation of this manga as a basis to fansub the anime, I will put your username in the fansub credits by default but tell me if you want to be left out".

I feel Like I'm being asked "If a fish could acorn would that be morally acceptable?" and I am honestly at a loss.

When I initially posted my previous comment, all 3 answers were within 1% of each other. The difference has grown a lot since then.... I wonder if the voters actually read these comments without replying, to influence their votes.